No. 551] 



NOTES AND LITERATURE 



It is doubtful whether the derivation of the Anthocerotaceas 

 from the Spluerocarpales will be generally accepted. For the 

 present, at least, the order must be regarded as a very isolated 

 one, and perhaps best considered to represent a distinct class. 



Douglas Houghton Campbell 



INVERTEBRATES 



Undee the able leadership of Professors Zeigler and Woltereck 

 there is appearing from Klinkhardt's press in Leipzig a series 

 of excellent small monographs of familiar animals designed for 

 the student, teacher, investigator and amateur who desires to 

 secure a brief but authentic account of the results of systematic, 

 histological, morphological, anatomical and embryological investi- 

 gations on representative types of animals. Two volumes have 

 already appeared, the frog by Dr. Hempelmann, and the rabbit 

 by Dr. Gerhardt, and the series of invertebrates has been 

 introduced by two volumes, volume 3 of the series on "Hydra 

 und die Hydroiden" by Dr. Steche, of Leipzig, and volume 4 by 

 Professor Meisenheimer, of Jena, on "Die Weinbergschnecke. 



Dr. Steche 's volume is designed not merely as a monograph 

 on Hydra along the lines on which the series is planned, but 

 adds to these the features of an introduction to the experimental 

 treatment of biological problems as offered by the lower ani- 

 mals. Hydra is an exceptionally favorable subject for this 

 treatment by virtue of its hardiness, ease of obtaining and of 

 maintenance, and simplicity of structure. Few invertebrates 

 have served as a basis of so many and so varied experimental 

 tests and have been the object of so many investigations as 

 Hydra. With this wealth of results before him it is not to be 

 wondered at that this modest volume is open to the charge of 

 some sins of omission. The choice of topics treated is, however, 

 most catholic and this author has wisely avoided controversial 

 difficulties. The histological and embryological sections are less 



'"Monographien einheimischer Tiere," Herausgegeben von Professor 

 Dr. H. E. Ziegler, Stuttgart, und Professor Dr. E. Woltereck, Leipzig, Bd. 3; 

 "Hydra und die Hydroiden. Zugleich eine Einfiihrung in die experimentelle 

 Behandlung biologischer Probleme an niederen Tieren," von Dr. Otto Steche, 



+ 162 pp., 65 figs, in text and 2 pis., M. 4, geb. M. 4.80; Bd. 4, "Die 

 Weibergschnecke, Helix pomatia," von Professor Johannes Meisenheimer, 

 140 pp., l p i. and 72 figg. i n text, M. 4, geb M. 4.80. 



