eries experts, to spend a couple of years in exploring more systematically than has yet been done, or can otherwise be done, our British coasts from the Laminarian zone down to the deep mud. No one could be better fitted to organise and direct such an expedition than Dr. John Murray.

Such a detailed survey of the bottom and of the surface waters, of their condition and their contents, at all times of the year for a couple of years, would give us the kind of information we require for the solution of some of the more difficult fishery problems such as, the extent and causes of the wanderings of our fishes, which nurseries' are supplied by particular spawning grounds, the reason of the sudden disappearance of a fish such as the haddock from a locality, and in general the history of our food fishes throughout the year. It is creditable to our Government to have done the pioneer work in exploring the great oceans, but surely it would be at least equally creditable to them and perhaps more directly and immediately profitable, if they look for some such return from scientific work-to explore our own seas and our own sea-fisheries.

There is still another subject connected with the fisheries which the biologist can do much to elucidate-I mean the diseases of edible animals and the effect upon man of the various diseased conditions. It is well known that the consump tion of mussels taken from stagnant or impure water is sometimes followed by severe symptoms of irritant poisoning which may result in rapid death. This 'musselling' is due to the presence of an organic alkaloid or ptomaine, in the liver of the mollusc, formed doubtless by a micro-organism in the impure water. It is clearly of the greatest importance to determine accurately under what conditions the mussel can become infected by the micro-organism, in what stage it is injurious to man, and whether, as is supposed, steeping in pure water with or without the addition of carbonate of soda will render poisonous mussels fit for food.

During this last year there has been an outcry, almost amounting to a scare, and seriously affecting the market,' as to the supposed connection between oysters taken from contaminated water and typhoid fever. This, like the musselling, is clearly a case for scientific investigation, and, with my colleague Professor Boyce, I have commenced a series of experiments and observations, partly at the Port Erin Biological Station, where we have oysters laid down on different parts of the sbore under very different conditions, as well as in dishes and tanks, and partly at University College, Liverpool.

Our object is to determine the effect of various conditions of water and bottom upon the life and health of the oyster, the effect of the addition of various impurities to the water, the conditions under which the oyster becomes infected with the typhoid Bacillus, and the resulting effect upon the oyster, the period during which the oyster remains infectious, and lastly, whether any simple practicable measures can be taken (1) to determine whether an oyster is infected with typhoid, and (2) to render such an oyster innocuous to man. As Professor Bovce and I propose to lay a paper upon this subject before the Section, I shall not occupy further time now by a statement of our methods and results.

I have probably already sufficiently indicated to you the extent and importance of the applications of our science to practical questions connected with our fishing industries. But if the zoologist has great opportunities for usefulness, he ought always to bear in mind that he has also grave responsibilities in connection with Fisheries investigations. Much depends upon the results of his work. Private enterprise, public opinion, local regulations, and even imperial legislation may all be affected by his decisions. He ought not lightly to come to conclusions upon weighty matters. I am convinced that of all the varied lines of research in modern zoology, none contains problems more interesting and intricate than those of Bionomics, Oceanography, and the Fisheries, and of these three series the problems connected with our Fisheries are certainly not the least interesting, not the least intricate, and not the least important in their bearing upon the welfare of mankind.

I am told that between December and March the oyster trade decreased 75

per cent.

List of Species taken in one haul, on June 23, 1895 (see p. 705).

The following Reports and Papers were read :—

1. Third Report on the Marine Zoology, Botany, and Geology of the Irish Sea.-See Reports, p. 455.

2. Interim Report on the Migration of Birds.-See Reports, p. 473.

3. Fifth Report on the Zoology of the Sandwich Islands.
See Reports, p. 467.

4. Report on the Occupation of a Table at the Zoological Station at Naples. See Reports, p. 474.

5. Report on Investigations made at the Laboratory of the Marine Biological Association at Plymouth.-See Reports, p. 469.

6. Report on the Investigation of the Zoology and Botany of the West India Islands.-See Reports, p. 472.

7. Report on the Compilation of an Index Generum et Specierum
Animalium.-See Reports, p. 473.

8. Report on Physiological Applications of the Phonograph.
See Reports, p. 454.

9. Some Remarks on the Stereornithes, a Group of extinct Birds from South America. By C. W. ANDREWS.

A brief history of the discovery of these remarkable birds is given, together with a short account of the more important opinions that have been expressed concerning their affinities.

The structure of the skeleton of Phororhacos, recently described by Ameghino, is considered, and, after comparison with certain other birds, some suggestions are made as to the probable affinities of the genus. Phororhacos is regarded as a true carinate bird, in which, as in the dodo, aphanapteryx, and many others, the wings have undergone reduction through disuse. It seems to have been a highly specialised form, and probably has left no direct descendants: its nearest relatives may perhaps be found among the Gruiformes, especially in the Psophiida and Dicholophi, and it possibly represents a specialised offshoot from the generalised stock which gave rise to these forms. No special affinities with the living Ratitæ are found, and it appears very doubtful whether Gastornis is any way related.

The other genera described by Ameghino are much less completely known; some of them, however, differ so considerably from Phororhacos, and in several cases from one another, that they should probably be referred to several distinct families, as, indeed, has already been done by Moreno and Mercerat. The Stereornithes, therefore, appear to include a somewhat heterogeneous group of birds, whose chief points of resemblance seem to lie in their large size and more or less reduced power of flight. The unfortunate absence of specimens of these interesting fossils from

the European museums renders any detailed comparison with existing forms impossible, so that the opinions expressed in the present paper must be regarded as provisional only.

10. Some Facts and Reflections drawn from a Study of Budding in Compound Ascidians. By Professor W. E. RITTER (University of California).

Numerous recent writers have doubted the genetic unity of the compound ascidians; i.e., they have doubted whether their property of budding, the character which all agree to be the final test of whether an ascidian is simple or compound, has not been acquired more than once. Of these authors I may mention Lacaze-Duthiers, E. van Beneden, Herdman, Seeliger, Lahille, and Sluiter.

In discussing the subject van Beneden has made the apt remark that no zoologist would think of uniting all bud-producing actinians in one group and placing them over against all others that do not reproduce in this manner. In his wellknown report on the compound ascidians of the 'Challenger' Expedition, Professor Herdman not only reached the conclusion that the group is polyphyletic in origin, but he also marshalled his broad knowledge to show that they probably originated at three distinct points from the simple ascidians, and to show also what genera trace their origin back to each of these three starting-points. The author regarded this as one of the most important generalisations reached by his study of the great 'Challenger' collection.

Quite recently M. Lahille has proposed an entirely new classification of the Tunicata, in which he ignores budding as a diagnostic character of at most greater than generic importance. That, however, this writer has treated the matter too lightly, whether regarded from a morphological or a physiological point of view, will, I apprehend, be allowed by most students of the group.

It is not my purpose to discuss here a classification of the compound ascidians based on the hypothesis of their polyphyletic origin, but rather to show, first, that they have had such an origin, and, secondly, to consider certain developmental probabilities that are involved in, or, rather, are the necessary results of, such an hypothesis.

In the interest of brevity and clearness my discussion will aim almost entirely at showing that two genera of compound ascidians are, structurally considered, considerably more unlike each other than each is unlike a genus of simple ascidians which, in turn, are widely separated from each other.

The genera to which I refer are Perophora and Goodsiria as representatives of the compound ascidians, and Ascidia and Polycarpa as representing the simple ascidians.

Definitely stated the proposition to be established is this: Perophora and Goodsiria are less closely related to each other than on the one hand Perophora is to Ascidia, and on the other Goodsiria is to Polycarpa.

We will first compare the several genera anatomically, and afterwards the budding in Perophora and Goodsiria; and we may begin with Polycarpa and Goodsiria. Polycarpa is closely related to Cynthia, and still more closely to Styela. The genus is, however, distinctly separated from Cynthia, particularly by its possessing simple tentacles and sexual organs in the form of so-called polycarps.

Goodsiria belongs to the Polystyelidæ, a small family of compound ascidians, founded by Professor Herdman for the reception of several genera that are, as our knowledge now stands, closely related to one another, and well separated from all other compound ascidians, although they certainly have rather close affinities with the Botryllida.

The close similarity in structure between Polycarpa and the Polystyelidæ has been recognised by nearly all investigators who have studied them, and my own work has, I think, shown their kinship to be even closer than has heretofore been supposed. In fact, the resemblance is so close between an undescribed species of

Polycarpa which I have found on our Californian coast and Goodsiria dura from the same locality that I am sure no zoologist would ever think of recognising more than a specific difference between them, did not the one reproduce by budding while the other does not. Two points, however, must be briefly dwelt upon-one of resemblance, the other of difference.

It is well known that the hypophyseal duct in ascidians is usually situated on the ventral side of the ganglion; but it is also well known that Botryllus forms an exception to this rule, for in this species the duct is dorsal to the ganglion. I find that Goodsiria agrees with Botryllus in this peculiarity. I also find that the only species of Polycarpa which I have examined with reference to the point, viz., Polycarpa pomaria, possesses the same unusual character. In some cases, at least, it is well nigh, if not wholly, impossible to ascertain the relation of the duct to the ganglion without the aid of sections. It appears to me, consequently, that the occurrence of this very exceptional condition in both Polycarpa and Goodsiria, when considered together with their many other close resemblances, adds considerable weight to the belief in their close kinship.

The difference to which I refer is the presence usually of well-marked folds in the branchial sac of Polycarpa and the rudimentary condition or entire absence of these folds in Goodsiria. In the sac of Goodsiria dura there is no trace of folds proper, but two of the five internal longitudinal vessels on each side of the sac are distinctly nearer together than are the others. A similar approximation of these vessels where no true folds exist occurs in numerous species of ascidians, and Herdman has given good reasons for regarding it as evidence of folds that have been lost. The vessels are usually crowded on the folds more than elsewhere; the folds in some cases disappear, but the crowded vessels, being a deeper morphological character, persist though on a plain surface. Now it can be shown that in genera where these folds are present as a rule, but where they may be rudimentary or absent, it is, in a general way, in the larger species that they are best developed, and in the smaller ones that they are rudimentary or absent. From this fact and others I am disposed to look upon Goodsiria as a pigmy Polycarpa.

Next, concerning the structural likenesses between Ascidia and Perophora, they are close in most points and not remote in any. Perhaps the most important difference is found in the branchial sacs, but this difference is interesting. Ascidia has internal longitudinal vessels which are papillated, while Perophora has no internal longitudinal vessels; but it does have long interserial papillæ, each of which is provided with two processes of variable length, one directed anteriorly, the other posteriorly. Now if these processes on one series of the papilla were to reach across and unite with the corresponding ones of an adjacent series of papillæ, internal papillated longitudinal vessels would be produced entirely similar to those existing in Ascidia. Suggestively enough, individuals of at least two species of Perophora have been observed in which just such a union does exist. From this it would appear that the lateral processes of the papillæ in Perophora are remnants of internal longitudinal vessels; and this fact, taken in connection with others, inclines me to regard Perophora as a pigmy Ascidia, just as we have seen that Goodsiria may be regarded as a pigmy Polycarpa.

In comparing Goodsiria and Perophora on the one hand and Polycarpa and Ascidia on the other, we find a marked contrast in each case in nearly every organ of the body.

Turning to reproduction by gemmation, the buds of Perophora are produced by a proliferous stolon, while those of Goodsiria are formed directly from the body of the parent zooids, the inner layer of the bud being an evagination of the parietal wall of the peribranchial sac. Are these two methods of origin of buds reducible to a common type? I may say at once that a conclusive answer to this query is not yet possible, for the reason that we do not know how the first bud, i.e., the bud from the embryozooid, arises in either genus.

I cannot leave this part of the subject without saying a single word about the epicardium, a structure that is certainly of much importance in connection with the budding of many compound ascidians. The only structures in Goodsiria that