ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 361 



Frontonia leucas.* — Abraham Brodsky has made a detailed study 

 of this Ciliate. The ectoplasm includes not only homogeneous and 

 alveolar layers, but also a granular layer composed of spherical granules 

 imbedded in the homogeneous plasm and covering the whole surface. 

 Both in cytoplasm and nucleoplasm there is an alveolar basis and 

 granules. In the micronucleus the alveoli are most minute. The 

 trichocyst is highly differentiated, showing head, neck, and body. Its 

 explosion is the result of a chemical reaction produced by the entrance 

 of water. The buccal structures show a combination of Trichostome 

 and Gymnostome features. There are two oral membranes, of which 

 the larger is undulatory. The buccal cavity and gullet are surrounded 

 by strong rodlets. 



The numerous micronuclei are lodged in deep pockets in the 

 membrane of the macronucleus. The mass of cytoplasm is almost 

 strictly proportional to the mass of nucleoplasm. During its division 

 the macronucleus passes through stages parallel to those in the division 

 of the micronucleus. Its substance differentiates into chromatin and 

 linin. 



Infusorians in Holothurians.f — P. de Beauchamp reports that he 

 found at Banyuls in the respiratory tree of Cucumaria planet, the two 

 interesting Infusoriaus which Stevens found in Holothuria californica 

 from the Gulf of California, viz. : Licnophora macfarlandi and Boveria 

 subcglindrica. 



Studies on Volvox.J — J. H. Powers describes Volvox spermatospliara 

 sp. n., V. ■weismannia sp. n., and V. perglobator sp. n. It is possible to 

 arrange the known species in a series: — V. spermatosphara, lowest 

 because of its Eudorina-like sperm-spheres, its lack of cytoplasmic 

 cell-connections, its small size, etc. ; just above it V. weismannia ; then 

 V. fortius, V. aureus {minor), V. globator, and highest of all V. perglo- 

 bator. " The detailed phenomena of reproduction in V. spermatosphara, 

 and still more in V. weismannia, seem to yield strong support to the 

 hypothesis that nutritive causes, manifesting themselves especially in 

 the size of the cells, are an important factor in determining the sex of 

 the reproductive cells or their products in these incipient multicellular 

 organisms." 



Macronucleus of Ciliata.§ — E. Faure-Freiniet has used the " ultra- 

 microscope " in studying the structure of the macronucleus. It is full 

 of refractive microsomes very close together. When a solution of 

 soda is added these granules disappear. The macronucleus behaves like 

 a negative colloidal solution with closely approximated granules. Its 

 structure depends on the reaction of the medium surrounding it. 



New Species of Chilodon on Fishes. || — E. Kiernik describes 

 Chilodon hexastichus sp. n., an Infusorian found on tench, carp, and 



* Rev. Suiss. Zool., xvi. (1909 pp. 75-130. 



t Bull. Soc. Zool. France, xxxiv. (1909) pp. 6-7. 



t Trans. Amer. Micr. Soc.xxviii. (1908) pp. 141-75 (4 pis.). 



§ Bull. Soc. Zool. France, xxxiv. (1909) pp. 55-6 (1 fig.). 



|| Bull. Internat. Acad. Sci. Cracovie, 1909. pp. 75-119 (3 figs.). 



