NoVEMUEl! 10, ISSo.] 



SCIENCE. 



659 



Scutibrauchs at all, in our opinion. Kxcliuling 

 these, which refer only to the Docoglossa, it will 

 be observed that the onl}' difference (according 

 to the definitions) between the two orders is, 

 that the latter has a holostomate shell. I-^very- 

 bodj- knows that a large proportion of the 

 pectiuibranehs of Tryon are holostomate, that 

 is, have an entire aperture without a canal : for 

 instance, Sealaria, Cyclostoma, Litorina, etc. 

 What, then, becomes of the two orders? As a 

 rule, the definitions are deficient in not giving 

 essential characters, even when the groups de- 

 fined are perfectlj- valid, and redundant in 

 giving characters belonging to groups of dif- 

 ferent rank from the one defined, or of no par- 

 ticular value. 



Of small errors we have noted not a few ; 

 but it is probable that a book of this kind 

 must be expected to have a certain number, 

 and completeness can hardly be looked for. 

 However, the author has brougiit together an 

 immense number of genera ; and the work, 

 when the index appears, will be very useful to 

 conchologists on this account, though it would 

 have been more so, had each genus been given 

 a date, since, in general, there are no refer- 

 ences. The coloration of the plates, also, is 

 better than in the previous volume, and the 

 figures for tlieir kind are fairly good. The 

 work is well bound and on good paper, but 

 suffers from inferior printer's ink, which 'over- 

 laj's ' on nearly every page. 



In conclusion we may say, that, for use 

 as a text-book for fresh students, this work 

 would be decidedly- inadvisable ; but those 

 who have already- gained some knowledge of 

 modern classification, and of the anatomy and 

 physiology of mollusks, will find it to a certain 

 extent useful, though by no means to a degree 

 commensurate with the labor which has evident- 

 ly been spent upon it. 



ADAMS'S LECTURE ON EVOLUTION. 



Evolution: a summary of evidence. A lecture de- 

 livered in Montreal, March, 188.3, by RonERT 

 C. Adams. New York, G. P. Pttlnam's Sons, 

 1883. 44 p. 12°. 



Mu. Ai>AMS has attempted to summarize in 

 a single lecture the various kinds of evidence 

 that have been adduced in favor of the evolu- 

 tion of plants and animals, and the earth it- 

 self. The author claims to be nothing fiulher 

 than a compiler, and aims to present • an ab- 

 stract of many books ' in ' plain language.' As 

 he has not limited himself to any particular 

 class of evidence, nor confined his attention to 



any single object, or group of objects, it is 

 obvious that any attempt to treat in a single 

 lecture the wide range of subjects embraced 

 under evolution must prove a failure. It is 

 simply a jumble of facts, collected, for the most 

 part, from popular books and essays, with a 

 considerable admixture of error and miscon- 

 ception. A little familiarity with the more 

 recent discussions on the subject of the origin 

 of the vertebrates (for example, those of Dohrn 

 and Laukester) would have led our author to 

 verj- different views concerning ' the connecting 

 links ' between vertebrates and invertebrates, 

 and saved him the trouble of rehearsing ex- 

 ploded ideas respecting Amphioxus and the 

 ascidians, Anj' respectable text-book in sj's- 

 tematic zoology would have told Mr. Adams 

 that an ascidian is not a raollusk, that Kala- 

 ■noglossus is not regarded as an ' intermediate 

 form' between mollusks and such 'jointed ani- 

 mals ' as crustaceans and insects, and that 

 corals are not protozoa. 



The author's reference to intermediate forms 

 and 'connecting links' shows that he has not 

 grasped the ideas now generallj- received con- 

 cerning the genealogical relationship of ani- 

 mals. One or two passages will illustrate this 

 point. " If in twentA'-one days the chick 

 passes through the forms common to sponges, 

 siiell-fish, fish, and reptiles, does it not sug- 

 gest that its race may have developed through 

 these lower races during vast ages? If in 

 forty weeks a single man now develops through 

 forms common to all the lower races of ani- 

 mals, may not the race of man h.ive slowly 

 arisen through all the ranks of life below him, 

 each great division leaving its record in the 

 unfolding germ of the latest individual? . . . 

 Through the sponges we find the radiates con- 

 nected with the protozoans, or first forms of 

 life, such as corals and sea-animalcules." 



Under the head of ' Unity of substance ' we 

 are told that " the germs which produce men, 

 dogs, sheep, or any of the highest class of 

 animals, cannot be discovered to differ hy anj* 

 test of microscope or chemistrj'. . . . Each 

 individual begins life in the lowest form of 

 matter, and develops through forms common 

 to all the species below it. A man has by 

 turns the forms of the germs of plant, proto- 

 zoan, niollusk, articulate, and vertebrate — 

 fish, reptile, and mammal." 



The lecture abounds in such loose and inac- 

 curate statements as the above, and must 

 therefore be pronounced an unsafe guide to 

 ' the uninitiated,' to whom the lecture is espe- 

 cially- addressed. 



