ZOOLOGY AND BOTANY, MIOROSCOPYj ETC. 863 



paper Certes liad referred to the presence, in the stomach of an oyster, 

 of an amoeboid hyaline substance which, at first sight, appeared to be 

 a true Bathybius, but which, when treated with iodine, acetic acid, and 

 colouring matters was found to be a colloid body. How does this get 

 into the stomach of the oyster ? The recent observations of Mobius 

 on the rapid disappearance of the crystalline style in oysters taken 

 out of the water suggests that these amceboid masses are nothing else 

 than the debris of the crystalline style. 



Chrysopyxis bipes Stein (Dinobryon sertularia Ehrenb).* — 



N. Wille has made a careful examination of the organism described 

 by Woronin under the name Chromophyton Itosanqffii,f and details 

 the history of its development as follows : — After hibernation the 

 cells divide, and the zoospores, after swarming for a time, at length 

 come to rest, the anterior end with its contractile vacuole resting on 

 the substratum. Colourless protoplasm now begins to collect at the 

 opposite end, the enveloping membrane being somewhat raised up by 

 it and finally ruptured, a portion of the protoplasm escaping into the 

 water ; the membrane can now be compared to a flask-shaped envelope, 

 in the mouth of which is a fine protoplasmic cilium. In this state, 

 the organism appears to be identical with Stein's Chrysopyxis hipes ; 

 the same author's Ohrysomonas ochracea being the globular zoospores 

 which result from the division of its protoplasm. 



The above is the cycle of development of one form of Woronin's 

 Chromophyton, the one with many small globular zoospores, which 

 have their vacuole in the anterior part, at the point of origin of the 

 cilia. A second form has larger oval zoospores, and the vacuole nearly 

 in the middle of the larger diameter. In the hibernating stage it can 

 scarcely be distinguished from the first form ; but as soon as it com- 

 mences to divide, it is marked by the form, size, and position of the 

 contractile vacuole. This form is possibly Ehrenberg's Monas 

 flavicans (certainly not Stein's Chrysomonas flavicans). When the 

 bulging of the enveloping membrane begins, it becomes Epipyxis 

 utriciilus Ehrenb. Its protoplasm divides, usually by bipartition. 

 Eepeated division, resulting in the inclosing of several individuals 

 within the same envelope, leads to Ehrenberg's Dinohryon sertularia ; 

 in this stage a red eye-spot is perceptible. 



All the different forms which have been named appear therefore 

 to be stages in the cycle of development of a single organism. 



* Ofvers. Kngl. Vetenskaps-Akad. Forh. Stockhohn, 1882, pp. 9-22 (1 pi.). 

 See Bot. Oentralbl., xt. (1883) p. 33. 

 t See this Journal, i. (1881) p. 100. 



