April 8, 1910] 



SCIENCE 



543 



ample, as is given on page 3, of the chief 

 works on the cleavage of mammalian eggs, 

 should be highly appreciated by the general 

 student. 



There are in all six chapters, as follows: 

 I., The First Cell Layers— (A) Of the Mono- 

 delphic and Didelphic Mammals; (B) Of the 

 Ornithodelphic Mammals and Sauropsida, and 

 (C) Of the Ichthyopsida. II., Farther De- 

 velopment of the two Germ-layers of the 

 Vertebrata up to the Origin of the Somites. 

 The Mammalia, the Amphibia, the Saurop- 

 sida and Ornithodelphia and the Fishes are 

 treated. III., Diplotrophoblast-Serosa (Sub- 

 zonal) Membrane, Chorion, Allantois and 

 " Nabelblase " in Onto- and Phylogenesis. 

 IV., The part taken by the Trophoblast in the 

 Nutrition and the Attachment of the Embryo. 

 v.. Various Points (Versehiedenes) on Pla- 

 eentation. VI., Considerations Touching the 

 Phylogeny and the Systematic Divisions of 

 the Vertebrata. 



These contents of the chapters will suffice to 

 show that as regards embryology proper only 

 the very early stages are dealt with. Organo- 

 genesis does not fall within the scope of the 

 work. The undertaking is such, too, that 

 vertebrates other than mammals receive large 

 attention. Of the 186 figures nearly one 

 fourth are not mammalian, the larger number 

 of these outsiders being of fishes, amphibians 

 and reptiles. 



As to exactly how much weight should be 

 attached to Hubrecht's theory in its various 

 ramifications (his trophoblast theory) only a 

 student of the vertebrata can tell who is more 

 experienced than he, and is far less of a 

 special pleader. But any zoologist who is 

 moderately well informed first hand in general 

 vertebrate morphology and embryology, and 

 who has likewise occupied himseK in a serious 

 way with problems of phylogeny, can readily 

 see that the best that can be said for the most 

 far-reaching contentions is that they may 

 possibly be true. While it may be legitimate 

 for a zoologist to find a measure of satisfac- 

 tion in recognizing the various possibilities 

 as to what the course, or rather courses, of 

 vertebrate evolution may have been, it is well 



never to lose sight of the fact that what is 

 only possibly true is probably not true. 



Hubreeht has pointed out facts enough to 

 make it possible that his " vermactinial stage 

 in vertebrate phylogenesis," figured on page 

 22 and again on page 228, was a reality in 

 some remotely past time. But dozens of other 

 facts which he has not alluded to make it 

 probable, to the reviewer's mind at least, that 

 no such ancestral stage ever did exist. 



Such a hypothetical creature would be 

 harmless, indeed might have a certain useful- 

 ness, could it be presented merely as one 

 among numerous possibilities, for if so pre- 

 sented it would not be chargeable, as it is 

 almost sure to be when claiming exclusive 

 rights, with distorting the facts upon which 

 its existence depends; and it, along with its 

 alternatives, might then help the mind to 

 grasp the general truth that the actual ani- 

 mals dealt with have arisen by a natural, that 

 is, an evolutionary process. 



La Jolla, Cal. Wm. E. Eittek 



the silken-haired ones 

 What "Black Beauty" did for horses 

 President Jordan's " Story of Matka '" ought 

 to do for the unfriended fur-seals of the 

 Bering Sea. The ruthless slaughter of these 

 seals which will end, if not soon interrupted, 

 in their certain extinction, is a hideous pres- 

 ent-day world crime of which three great 

 powers are openly guilty. In 1880 two and a 

 half million fur-seals lived in Bering Sea. 

 In this year 1910 of enlightened civilization, 

 scientific knowledge and Christian sweetness 

 and light there are still by good fortune alive 

 150,000 of these beautiful, silken-haired, soft- 

 eyed —matures of nature's choicest making. 

 The Ouij.^-^ " have been slaughtered as mothers 

 or starved as children by the refined methods 

 of diplomacy cultivated by Great Britain, 

 Japan and the United States. 



Dr. Jordan wrote the " Story of Matka " on 

 the very rocks where Matka lived, with Matka 

 the mother seal and Kotik, the baby seal and 

 Atagh, the grandfather and Eichkao, the blue 

 ^ " The Story of Matka," by David Starr Jordan. 

 San Francisco, Whltaker-ay-Wiggin Co., 1910. 



