300 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



INVERTEBRATES. 

 Protozoans, Sponges, anil Worms. 



"Studies among Amoeba}" is the subject of an article in 

 the Popular Science Review for July, by Professor P. M. 

 Duncan, who describes the habits and figures of some of the 

 forms of these protozoans. Of the twenty or more species de- 

 scribed by German and English observers, Duncan believes 

 that there are but two truly specific forms, Amoeba villosa 

 and Amoeba princeps. 



Dr. Leidy has observed a species of infusorian, probably 

 Chilomonas, existing in immense numbers on the sandy beach 

 of Cape May, where they formed a thin yellowish-green film, 

 coloring the surface of the sand. 



An important work on the development of the egg has 

 been published by O. Biitschli, who is well known by his 

 studies on the Infusoria and the lower worms, especially the 

 Rotifera and the Nematode worms. As regards the process 

 of conjugation among the Infusoria, Biitschli, according to a 

 review of his work in JVature, thinks that it is merely a reju- 

 venescence of the creatures which undergo it, enabling them 

 to become " the stem ancestors of a series of generations 

 which propagate by fission." This is contrary to the view of 

 Balbiani, Stein, and others, who maintain that the act of con- 

 jugation so well known among the JParamecia, Vbrticelhe, etc., 

 is the precursor of a sexual mode of generation. The review- 

 ers, Messrs. Dallinger and Drysdale, disbelieve in Biitschli's 

 theory, and suggest that "what he calls rejuvenescence is one 

 of the many modes by which rapidity of fissiparous multi- 

 plication is in some organisms aided, and the necessity for 

 the true act of fertilization is made less frequent." 



The foraminiferous forms shall we say varieties or spe- 

 cies? of Barbadoes have been studied by Van den Broeck. 

 His material was received from the West Indies, having been 

 collected by the late Professor Agassiz. He concludes, with 

 all others who have studied these exceedingly variable forms, 

 " that the terms genus, species, variety, have a very different 

 and broader acceptation than we usually suppose." 



A severe critique on Dr. W. B. Carpenter's views regard- 

 ing certain groups of Foraminifcra, by Dr. G. C. Wallich, 



