ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 507 



is first displayed in the Myxomycetes. Pla&modiophora must be 

 regarded, notwithstanding the absence of a peridium, as an endo- 

 sporous Myxomycete. The formation of a peridium seems to be 

 rendered superfluous by its endophytic habit, its place being taken 

 by the cell- wall of the cell which serves as host. The author does 

 not consider the endosporous and exosporous Myxomycetes or CeratieaB 

 to be derived either from the other ; the latter are rather connected 

 with Yamjpyrella through Bursulla crystallina Sorot., which may be 

 regarded as a terrestrial Vampyrella, its sporangium corresponding, 

 on the other hand, to a spore of the CeratieaB. The fructification 

 (receptacle) of a Geratium may be regarded as an aggregation of a 

 number of Burmllce, with the difference that the " spore "-contents 

 have split up into eight pieces only after their escape from the cell- 

 wall, while in Bursulla the same process takes place within the cell- 

 wall. The endogenous Myxomycetes and the Ceratiete are therefore 

 parallel branches springing from the Vampyrellefe, and both ending 

 without any genetic connection with any higher organisms. 



Another branch of the Amoeboidese is constituted by Olpidiopsis, 

 Bozella, and Woronina, which Gobi combines into the family Myxo- 

 chytridieae, with which he considers that SyncJiytrium, united with these 

 genera by Cornu and Fischer, has no near relationship; since it 

 possesses, on one hand, a common sporangial wall, and on the other 

 hand is destitute of an amoeboid stage. The course of development of 

 the Myxochytridie^ closely resembles that of Monas and the Vam- 

 pyrellese. The ripe cyst gives birth to a number of motile biciliated 

 embryos, which, in search of nourishment, are always transformed 

 into amoeboids. The absence of any coalescence of amoeboids into plas- 

 modia is due to their endophytic habit. The chief point in which the 

 Myxochytridiefe differs from Monas, is that the zoogonidia are not 

 immediately transformed into amoeboids, but only after the previous 

 formation of a cell-wall. This phenomenon serves to explain the 

 derivation of the Hyphomycetes, the simplest representative of which 

 is Chytridium. If we suppose that the zoogonidium of a Myxochytridia, 

 after it has attached itself to its host and developed a cell-wall, no 

 longer renew its contents in the form of an amoeboid, but advances 

 to the stage of endosmotic nutrition, we have a true Chytridium. 

 MyzGcytium, Lagenidium, and Achlyogeton differ from Chytridium only 

 in their endophytic habit. The first two are nearly related to 

 Pythium, and lead to the Peronosporese, while the last must be re- 

 garded as the simplest form of the Saprolegniese. Ancylystes is also 

 a transitional form between the Amceboideee and the Hyphomycetes. 

 Through the pedicel-forming Chytridium laterale and C. olla, we 

 advance to the two-celled Bhizidium, and then to the typical hyphal 

 forms of the Hyphomycetes. In opposition, therefore, to De Bary 

 and Brefeld, Gobi regards the Chytridieee not as the result of 

 degeneration, but as a progressive series forming a link between the 

 Vampyrelleae and the Hyphomycetes. While in the Amceboideae the 

 amoeboid represents the entire vegetative development, in the simple 

 Hyphomycetes it occurs only temporarily in the form of zoogonidium, 

 disappearing entirely in the more highly developed forms. 



