3. On the Development of Cystocarp in Polisiphonia nigrescens. 4. An Exhibition of Algæ. By A. CHURCH, FRIDAY, AUGUST 10, The following Papers were read : 1. On the Relations of Protoplasm, By Professor E. VAN BENeden. 2. On the Periodic Variation in the Number of Chromosomes. 3. On Chlorophyll in Animals. DEPARTMENT OF ZOOLOGY, : The following Papers were read : 1. On the Origin and Morphological Signification of the Notochord. By Professor E. VAN BENEDEN. 2. On the Carpus of the Greenland Right-whale compared with those of Fin-whales. By Professor J. STRUTHERS, M.D., LL.D. In his preliminary notice in 1885 the author stated the general conclusion that he found diminution in the number of boues in the second carpal row from Hyperoodon to Mysticetus. The following further observations relate to the whalebone whales only. The species and number dissected were: two of Balana enysticetus, five of Balanoptera musculus, one of B. borealis, two of B. rostrata, and one of Megaptera longimana. Besides noting the surface grooves, horizontal sections were made, showing the lines of fibrous suture marking off the limits of the cartilages and bringing into view ossifications not seen on the surfaces. As the fibrous sutures uniting these flat-walled cartilages are so narrow and firm as to prevent movement, these cartilages must be regarded as individually functionless, and we are prepared to find differences between the species and variation among individuals of the same species. In regard to the first row of the three usual mammalian pro-carpals in Mysticetus the intermedium sends up a peak between the forearm bones, articulating with ulna as well as with radius, and the pisiform is widely separated from the ulnare, in both of these particulars contrasting with the finners. In the second row, instead of the usual four disto-carpals in mammals, Mysticetus has but one broad cartilage bone, supporting digits III. and II., and in part digit I. Digits IV. and V. are supported by the ulnare, digit V. in part resting on the ulna, so that, on the ulnar side, the ulnare represents the entire carpus. The ossifications in Mysticetus vary. In the 48-feet-long female, which may be reckoned adult or nearly so, the only bones ossified in the left carpus are the inter medium and ulnare, and largely so; in the right carpus an ossification occurs also in the disto-carpal, of medium size. The radiale is not ossified in either carpus. In the 35-feet-long male Mysticetus, in the right carpus (the left not obtained), three ossifications occur, but they are in the radiale, the intermedium, and disto-carpal, not in the ulnare. Moreover, in this two-thirds-grown Mysticetus the metacarpal of the pollex is fully ossified, while in the adult the pollex is entirely cartilaginous. In the finners, in the distal row, two cartilage bones, more or less ossified, occur normally, supporting the two greatest digits. In the 65-feet-long B. musculus these two are united into one bone, notches above and below and a groove on the surface indicating synostosis of two formerly separate bones. In three of the five B. musculus a disto-carpal was found supporting the inner of the four digits, cartilaginous in the 50-feet-long one and in the 60-feet-long one, and with a small ossification in the 653-feet-long one. In the 45-feet-long one there was no trace of this third disto-carpal, either bony or cartilaginous, nor was it present in the 36feet-long B. borealis, nor in either of the two adolescent B. rostrata. In the Megaptera, 40 feet long, the ulnare is a very broad bone, extending for over one-third of its breadth below the radius, thus occupying also the locality of an intermedium, and between it and the radiale occurs an undersized intermediate bone. These two latter form the entire carpus, as one row, between the radius and the massive radial metacarpal. Small ossifications occur in the radiale and in the ulnare to its ulnar side. The pisiform is, in the great finners, large and square-shaped; in B. rostrata, narrow and directed upwards; in Mysticetus, transversely elongated. Regarded by some as merely a sesamoid, it serves as a stretcher, giving breadth to this broad part of the limb, steadied by the flexor carpi ulnaris muscle, which the author has found to be present in all the cetacea he has dissected, whether whalebone or toothed. In the 60-feet-long B. musculus it had an ossification as large as a walnut. The pisiform may be said to be the only one of these bones adapted to serve a function. The mass of cartilage forming the carpus serves to give some low flexibility and elasticity at that part of the limb, like a piece of firm indiarubber in the middle of an oar; but the mapping into distinct cartilage bones, more or less ossified, in these whales can be explained only on the view of inheritance from some mammal whose diarthrodially jointed carpal bones were adapted to allow of particular movements. 3. On the Species of Amphioxus. By J. W. KIRKALDY. I. Branchiostoma Lanceolatum (Costa). Distribution. Mediterranean Sea, English Channel, North Sea, Coast of Norway. Gonads 26 pairs. Both metapleural folds die away behind the atriopore. Myotomes 35, 14, 12. Snout fin of medium size, pointed. Caudal fin lancet-shaped. II. Branchiostoma Californiense (Cooper). Distribution.-Coast of California. Gonads 31 pairs. Both metapleural folds die out behind the atriopore. Myotomes 45, 17, 9. Head region very small, snout fin not marked off from the dorsal fin. Tail fin long and shallow. III. Branchiostoma Belcheri (Gray). Distribution.-Borneo and Torres Straits, Australia. Gonads 25 pairs. Both metapleural folds die out behind the atriopore. Myotomes 37, 17, 10. Snout fin long. Caudal fin wide and short. IV. Branchiostoma Caribæum (Sundevall). Distribution.-East Coast of S. America, Gulf of Mexico, West Indies. Both metapleural folds die out behind the atriopore. VI. Heteropleuron Cultellum. Branchiostoma Cultellum (Willey). Distribution.-Torres Straits, Australia. Right metapleuron continuous with the caudal fin. Dorsal fin very high. Both metapleura meet at the anterior end of the pre-oral chamber, and are continuous with the snout fin. Oral hood far back, and with few cirri, of which two sets, about a median cirrus, are webbed. Gonads 29, unpaired. Right metapleuron continuous with the caudal fin. Left metapleuron dies away behind the atriopore. Long caudal extension. DEPARTMENT OF BOTANY. The following Papers were read :- 1. On the Phylogenetic Position of the Chalazogamic Amentiferæ. The author reviewed the points of resemblance that obtained between the Cupuliferæ and the four chalazogamic genera, Alnus, Betula, Corylus, and Carpinus, and was led to the conclusion that, with the exception of the difference in the route of the pollen tube and the concomitant adaptations, no fundamental distinctions could be drawn between the chalazogamic and porogamic genera. The author also described and exhibited some abnormal inflorescences of Fagus sylvatica, Quercus Ilex, and Alnus glutinosa, and suggested atavism as their explanation. 2. On the Hygroscopic Dispersal of Fruits in certain Labiates. 3. On the Hybridisation of Orchids. By Dr. JAMES CLARK. 1. Interim Report on a Digest of the Observations on the Migration of Birds at Lighthouses.-See Reports, p. 348. 2. Report on the Legislative Protection of Wild Birds' Eggs. 3. Report on a Deep-sea Tow Net. 4. On Temperature as a Factor in the Distribution of Marine Animals. By Dr. O. Maas. In the question of the influence of temperature on marine animals no sufficient distinction has been made hitherto between three classes of facts: 1. Between the animals of the Plankton, the Benthos, and the Nekton. The eurythermal animals cannot be appealed to in proof of anything regarding temperature. For the stenothermal the average temperature of a locality is of small zoogeographical value, while the extent of variation is the most important factor. The Nekton animals are more eurythermal; otherwise their power of swimming, which brings them into very different conditions of temperature, would be of no use to them. The Plankton and Benthos animals are (with some exceptions discussed) more stenothermal; hence results the known division of the coasts. A distribution of the animals of the open ocean into regions is possible too, chiefly on account of the currents. Some instances of that were given from the facts of the Plankton expedition, chiefly of the Medusa, which have been worked out by Dr. Maas. Most interesting in this regard are the Geryonids, which in every ocean basin do not exceed a certain N. or S. latitude, and which as Plankton animals occupy a similar portion of the map as the corals of the Benthos. Dr. Maas is led to the conclusion that a comparison between the vertical differences and those found in higher latitudes can only be carried to a limited depth. The horizontal distribution of the pelagic fauna is not compensated by the vertical differences. There are no various belts of vertical life; the intermediate fauna between the Plankton of the surface and the Benthos of the abyss may be supposed to be only Nekton. This is valid for the deep sea. In lower seas the life may be continuous from the surface to the bottom. Sometimes special conditions, especially of temperature, prevail (e.g., in the Mediterranean, where a depth of 2,000 m. shows 13°). The occurrence of a deep-sea pelagic fauna, neither belonging to the surface nor in connection with the ground, as well as the survival of deep-sea animals coming to the surface, may be explained by this higher temperature. 5. Second Report on the Zoology of the Irish Sea. 6. On Marine Fish-hatching and the Dunbar Establishment of the Fishery Board for Scotland. By Professor W. C. MCINTOSH, F.R.S. It was stated that we are yet in doubt as to the beneficial effects to the fisheries of the artificial hatching of sea-fishes, but that the importance of the issue demanded a thorough trial. Several nations, such as the Americans and Norwegians, had chiefly experimented with the cod, other forms having been dealt with in small numbers. Though the sole was selected as the most suitable species, the lateness of its spawning period gave an opportunity for a preliminary series of experiments with the plaice. Accordingly a total of 396 plaice were collected, the average size of the males being about 17 inches, and that of the females about 20 inches. From these 27,350,000 ova were obtained, hatched in the boxes (Dannevig's), and the larval plaice-to the number of 26,060,000-sent into the sea, the loss in the process being only about 4.4 per cent. At Dunbar the eggs are shed in the spawning-pond, and carried to the spawncollector by the current. They are then counted and placed in the hatchingboxes. The sea-water for these is passed through a series of flannel-filters, so as to secure purity. Moreover, besides the current entering the end of the box, an upand-down movement is communicated to them twice every minute, so that the ova are evenly distributed through the water. On the whole the operations for the first year were most successful.1 DEPARTMENT OF BOTANY. The following Papers were read :— 1. On the Correlation between Root and Shoot. By Professor L. KNY. A full account of the experiments will be given by Dr. Fulton in the forthcoming Twelfth Annual Report of the Fishery Board for Scotland. |