364 



NATURE 



\Aiig. 29, 1872 



Oftopiis vulgaris proves to be the more dirficult to obtain. Two 

 specimens of Sifia officiitalis were placed in tlie pond on the Sili 

 of June, 1S71. Ori the I2lh July the female died, and was 

 found to coniain a l,irije<iuantity of ova. Steps have been taken 

 to have constructed in the cave behind the pond a case with a 

 glass front for watching the habits of animals. The temperatiiie 

 ol the water in the pond is several degrees below that in the tanks 

 at the Crystal I'alace. 



77/,' Mollnsca of Europe compared zvilh those of Eastern Xorlh 

 Amcriea, by J. G\vyn Jeffreys, F.R.S. 



After mentioning that he had dredged last autumn on the 

 coast of New EngUnd in a steamer provided by the Government 

 of the United .States, and that he had inspected all the principal 

 collections of Mollusca made in Eastern North America, the 

 author compared the Mollusca of Europe with those of Mai^a- 

 chusetts. He estimated the former to contain .about 1000 species 

 (viz. 200 land and fresh water, and 800 marine), and the latter to 

 contain about 400 species (viz. no land and freshwater, and 290 

 marine) ; and he took Mr. Binney's editii.n of the late Professor 

 Gould's Reporton the Mollusca of Massachusetts as the standaid 

 of comparisons. That work gives 407 species, of which Mr. Jelf- 

 reys considered 40 to be v.arieties, leaving 367 apparently dislnict 

 species. About thirty species may be added to this number in 

 consequence of the recent researches of Prof. VcrriU and Mr. 

 Wliiteaves on the coast of New England and the Gulf of St. 

 Lawrence. He identified 173 out of the 367 Massachusetts 

 species as European, viz. land and freshwater 39 (out of 1 10), 

 and marine 134 (out of 257), the proportion in ttie former cise 

 being 28 per cent, and in the latter 52 per cent. ; and he pro- 

 duced tabrlatei lists of the species in supporc of his statement. 

 He proposed to account for the distribution of the No.'th 

 American Mollusca thus identified by showing that the land and 

 freshwater species had probably emigrated from Europe to 

 Canada through northern Asia, and that most of the marine 

 species must "have been transported from the arctic seas hy 

 Davis's Strait current southward to Cape Co I, and the remainder 

 from the Mediterranean and western coasts of the Atlantic, by 

 the Gulf Stream in a northerly direction. 



Dr. Sclater said that it had always been an interesting prob'en 

 how the similarity of the Fauna of North Europe and North 

 America had been brought about. It was formerly supposed 

 that a continuous land area e.\isted between the two continents 

 in the neighbourhood of (Jreenland. He was quite disposed tj 

 aj^ree, however, that the communication hai been brought about 

 through the northern parts of Asia. In fact the fauna of Western 

 AmerTca and of Eastern Asia had gre iter points of similarity than 

 those of'Northern Europe and Eastern America. For example, 

 Ursus horrilnlis of Western America was intrinsically connected 

 with U. Arctos if not merely a form of it. There were also 

 some peculiar mammals which were identical; for example, an 

 Insectivore L-rotruhiiswzis common to Japan and North Western 

 America. With regard to birds several European types ha\'e 

 turned up also in North Western America, a true BuUtinch for 

 example. 



Prof AUman said that the distribution of Hydroids hardly 

 accorded with that of Molluscs. Amongst recently collected 

 Tiibiilaridci which he had eximined, and all of which were new, 

 two species only were common to both sides of the Atlantic. Our 

 own islands, the coasts of Norway, Iceland, and Greenland, and 

 the northern shores of the Atlantic down to Southern Nova 

 Scotia belonged to one Large province. At Florida all Eastern 

 forms die out. Amongst the West Indian islands not a single 

 species was common to both sides of the Albntic. Looking at 

 the facilities for distribution afforded by the locomotive buds of 

 these organisms, these facts were not easy to understand. 



Prof Thiselton Dyer said that plant distribution quite supported 

 the theory of communication between Asia antl America. Prof 

 A.a Gray had shown that the Flora of Japan had a strong 

 aliinity to the North West American. Griseb'ach had endeavoured 

 to invalidate this, but as Mr. Pentham said in his recent address, 

 with little success. It was remarkable to find in a case like this 

 an accordance between the facts of animal and plant distribution, 

 because in the case of the Malayan Archipelago plants of the 

 Iiido-Malayan type extended far to the east of the limits Mr. 

 Wallace found to exist in the case of animals. 



Mr. M'Lachlan as confirming Dr. Sclater's remarks concerning 

 the similarity of the fauna of Siberia and Eastern Asia with North 

 America, stated that several genera of Insects are common to the 

 two districts, though absent in Europe. He instanced especially 

 the neuropterous genus Pteronarcys which formed the subject of 



a well-known memoir by Newport on the occurrence of external 

 breathing filaments in the perfect kind of insect. 



Mr. Jeffreys in reply, instanced some cases of marine shells 

 which are common to the western or Pacific, and eastern or 

 Atlantic coasts of North America ; one of these is Verl'uorJia 

 aciitecoslala, which was at first known only as a tertiary fossil, 

 but h.as lately been found living not only in the European 

 seas, but also in the Gulf of Mexico, Japan, and probably 

 Davis's Straits. 



M. de Macklay had ascertained the existence of a species of 

 sponge both in Japanese and Norwegian waters. 



DEI'ARfMENT OF An.\TOMY A.ND PHYSIOLOGY 



On tlic Arrans;eiiient and Nomenclature of the Lohes of the 

 Liver in iVammalia, by Prof. W. H. Flower, F. R. S. 



The description of the livers of various animals to be met with 

 in treatises or memoirs on comparative .anatomy are generally 

 very difficult to understand for want of a uniforrrr system of 

 nomenclature. The present communication, which endeavours 

 to supply such a system (and was illustrated at the meeting by a 

 large series of coloured diagrams), is based upon an examination 

 of the condition of the organ in exain])les of every important 

 sub-division of the class. The difficulty usually met with arises 

 from the circumstance of the liver being divided sometimes, as in 

 man, ruminants, and the cetacea, into two main lobes, which 

 have always been called respectively right and left ; and in other 

 cases, as the lower monkeys, carnivor.a, rodentia, &c., into a 

 larger number of lobes. Among the latter, the primary division 

 usually appears at first sight to be tripartite, the whole organ 

 consisting of a middle, called " cystic," or "suspensory," lobe, 

 and two lateral lobes, called respectively right and left lobes. This 

 introduces confusion in describing livers by the same terms 

 throughout the whole series of mammals, as the right and left lobes 

 of the monkey, or dog, for instance, do not correspond with the 

 parts designated by the same names in man and the sheep. 

 There are, moreover, conditrons in which neither the bipartite 

 nor the tripartite system of nomenclature will answer, which we 

 should have considerable difficulty in describing, without some 

 more general system. 



It appears desirable to consider all livers as primarily divided 

 by the umbilical vein into two segments, right and left. This 

 corresponds with its development, and with the condiion 

 characteristic of the organ in the inferior classes of vertebr.ates. 



Desceiption of Figure. 

 Dla^r.iTiiin.itic plan of tlie inferior surface of a mulrilobed liver of a mam- 

 m.il extended transversely. Ttie posterior or attached border is uppermost. 

 «, umbilicil vein of the fretus, represented by the round ligament in t e 

 adidt, lying in tlie nmbihcal fissure ; dv, the dnctns venosus ; f r, the in- 

 ferior vena cava ; /, tfie vena portx entering the transverse fissure : / //", 

 the left lateral fissure ; r If, the right lateral fissure ; cf, the cystic fissure ; 

 //.the left lateral lobe; /c, the left central lobe; r r, the right central 

 loli'e : r /, the right lateral lobe ; s, the Spigelian lobe ; <-, the caudate lobe ; 

 g, the g.all bladder. 



The position of this division can almost always be recognised in 

 adult animals by the persistence of some traces of the umbilical 

 vein in the form of the round ligament, and by the position of 

 the suspensoi-y ligament. 



When the two main parts into which the liver is thus divided 

 are entire, they may be spoken of as the right and left lobes; 



