ZOOLOGY. 



7G5 



and this decision he gives as the result of observations by himself "for 

 months and even years, of forms living in the same locality." The 

 differences are manifested in the " average size, the consistency of the 

 protojilasm, and the movements thereby conditioned, as well as in the 

 characters of its contents, such as vacuoles, granules," and crystals, and 

 also, more especiolly, in the number, size, and structure of the nuclei. 

 Ten species are described by Dr. Gruber ; five of them are multi-nuclear, 

 and " it is proved how definitely the nuclei are distinguished from one 

 another, and with what certainty one can conclude from external char- 

 acters on the structure of the nucleus," and the reverse. It further 

 follows that " two very similar species of Amcebee may have very dif- 

 ferently-formed nuclei, and that in forms which are externally very 

 different the nuclei may be quite similar ; in any case, the number of 

 the different forms of nuclei is much more important than has hitherto 

 been supposed." 



The " only differentiation in the body of an Amoeba obtains at the 

 outermost periphery, where the protoplasm clearly, from contact with 

 water, is converted into an invisible cuticula-like layer, which disap- 

 pears during the outpushing of the pseudopodia and can be re-made." 



Dr. Gruber denies the existence of " a plexiform structure of the pro- 

 toplasm" as well as refractive bodies, such as have been described to 

 Pelomyxa jialustris. 



As to the " pale filaments" which have been found in some Amcebse, 

 they "appear to be symbiotic fungi;" "in one species, which was re- 

 markable for the constant collection of chlorophyll containing food, 

 they were always present." 



Among the species of Amoebae recognized by Dr. Gruber is the A. vil- 

 Zosn, first described by Dr. Leidy from specimens found about Philadel- 

 phia, and the discovery in Europe of this species " confirms the doc- 

 trine that the fresh-water Khizopods are cosmopolitan organisms." 

 {Zeitschr.f. rcissen. Zoolo., v. 41, pp. 186-225, 3 pi.; J. B. M. S. (2) v. 6, 

 pp. 260, 261.) 



Sporozoons. 



Development of Grerjorinids. — An imjiortant contribution to the devel- 

 opmental history of the monocysted Gregorines has been j)ublished 

 by G. Kuschhaupt. His observations were chiefly made on those in- 

 festing common earth worms or Lumbricids. Seven species of Grego- 

 rinids were found in the worms, which have been more fully described, 

 at least as to some points, by the author. The process of encystation, 

 the formation of sporoblasts, the presence of macrospores and micro- 

 spores in a single cyst, and the entrance of spores into the sperm- 

 mother-cell were especially observed in one or other of the Gregorinids 

 mentioned. The connection between the Gregorinids and the generative 

 products of the earth worms, the infection of earth worms with Grego- 

 rinids, and the relations between the parasites and coccidia have been 



