1G6 SUMMARY OF CURRENT RESEARCHES REIATINC TO 



one genus, e.g. Lacerta, there are species which live for a year or for two* 

 years and others which survive several decennia. 



The different sizes attained by different varieties or species seem to- 

 be related in the first instance to the diet, — that of carnivorous forms 

 depending on the size of the available victims. Those which eat small 

 creatures become sexually mature and reach their limit of growth sooner 

 than those which eat larger animals. There is a wealth of very inter- 

 esting information in this paper which we have only hinted at. 



Phylogenetic Speculations.* — H. Simroth discusses the origin of 

 vertebrates, sponges, and sexual reproduction, but his paper is very 

 elliptical, leaping over obvious difficulties and what seem to us necessary 

 steps in the argument. As might have been expected from the author 

 of The Origin of Land Animals, he re- emphasises the evolutionary 

 advantages of terra firma. It was on land that vertebrates were verte- 

 brated, the " Urstamm " being the " Tetrapoda," the place of origin 

 being probably the " East Pole." Even the head, he seeks to interpret 

 as " a product of terrestrial life." He refers the sponges to an origin 

 from terrestrial Acoela (Turbellarians), he derives the Accela from Infu- 

 sorians, and the Infusorians from " Probacteria " arising in the organic 

 matter which preceded life. Sexual reproduction is also a product of 

 the " Landleberi" which appears to have given initiative to all the more 

 important steps in evolution. Yv r e regret our inability to follow Prof. 

 Simroth's argument. 



Text-book of Zoology.! — A. Goette has written a text-book of 

 Zoology for serious university students, — a terse and accurate description 

 of animal forms from the comparative anatomist's point of view. Ac- 

 cording to the preface, it is intended to be distinctively evolutionist, 

 showing the progress of organisms from one grade of structure to another. 

 But we do not find any particular evidence of this in the text, and many 

 of the classifications are extremely conservative and dogmatic. There is 

 too little embryology, too little palaeontology, and too little cecology to- 

 justify the title ' Lehrbuch der Zoologie.' But it is the work of an 

 expert, who has done much for Zoology in the widest sense, and its 

 workmanship is good, though, as it seems to us, one-sided. 



Anomalies on Head-Shields of Snakes. + — L. H. Gough makes a 

 contribution to the study of variation by giving a list of the anomalies 

 in the head-shields of the snakes in the collections of the University of 

 Strassburg. The anomalies consist chiefly in a difference in the numbers 

 or arrangement of the shields (especially the temporals) on the two 

 sides of the head. 



Abnormal Coloration in Pleuronectids.§ — W. C. M'Intosh describes 

 a number of adolescent turbot showing a deep notch above the head, 

 the dorsal fin terminating in a prominent hook, and coloration on both 

 sides. He describes other cases of coloration on the under side on sole, 

 flounder, dab, and plaice. Such cases raise doubts as to whether illu- 

 mination is responsible for the development or non-development of 



* Verb. Deutsch. Zool. Ges., xii. Vers. (1902) pp. 152-62. 



t 'Lehrbuch der Zoologie,' Leipzig (Engelmann), Svo, xii. and 504 pp. andl 

 512 figs. X Zool. Jahrb., xvii. (1902; pp. 457-68. 



§ Ann. Nat. Hist., ix. (1902) pp. 291-308. 



