THE PROTEOMYXA 



resist desiccation, and are probably simple hypnocysts. 1 In other 

 cases the cysts are larger, and the contents give rise to three or 

 four (Vampyrella lateritia, Fig. 2) or a large number (Protomyxa, 

 x, Fig. 6, and Diplophysalis) of spores, which may be 

 either naked or protected by a membrane. These 

 cysts are protected by one or more cyst-membranes, 

 and the outer of these may be irregular or spiny or 

 gelatinous in texture. Occasionally three or four 

 small areas on the cyst-wall are provided with a 

 thinner membranous coat, and the spores escape by 

 breaking through these areas only (Haplococcus) ; but 

 Cystic phase of usua iiy the cyst-wall breaks down and liberates the 



Vampyrella. Ihe J J 



contents of the spores, or the spore escapes through any part of the 



cyst have divided , ' -T t i ii_ i 



into four equal membranes. In spore -formation the protoplasm 

 three' are f visible! usually discharges all extraneous matters, and one 

 (After Lankester large or a number of smaller granules of these 



and Cienkowski.) . i i?ri i 



ejecta are found between the wall of the cyst and 

 that of the spores. There is no evidence at present that any 

 process of conjugation occurs between the liberated zoospores, 

 except in Ciliophrys (Cienkowski), and, in the absence of any 

 systematic study of the nuclear substance of the spores, we are not 

 in a position to state that the condition of the nuclei or nucleo- 

 plasrn of the spores is in any way different to that of the other 

 phases of life. There is therefore no justification whatever for 

 the assumption that any form of cyst -formation indicates or is 

 associated with a sexual process. 1 



A remarkable phenomenon has recently been described by de 

 Bruyne in Leptophrys mllosa. After a period of feeding, the animal 

 becomes spherical in shape 

 and enters upon a period of 

 rest. From the surface there 

 are protruded a number of deli- 

 cate filaments (Fig. 3) which 

 terminate in hyaline globules. 

 These globules are discharged 

 and the filaments after some 

 time are slowly withdrawn. 



When conditions are 

 favourable there emerge 



from the Cyst One Or more Leptophrys vlllosa. A, a specimen actively feed- 

 /T j. ing, showing, v, a large non - contractile vacuole ; 



(iUOnadineae aZOO- d, the diatoms on which it is feeding ; and t, a tuft 



B. 



Fio. 3. 



<vr rmo /- 



< p 



of pointed pseudopodia at the posterior end of the 

 body. B, a resting stage of the same animal, pro- 



onnrAQA 



sporeae, j 



more flagellulae (Monadineae villed with filamentous processes, p, which discharge 

 r-r e\ mi minute globules, s.p, of hyaline protoplasm. (After 

 ZOOSpOreae, Zopf). Ihe deBruyne.) 



1 According to von Prowazek the nuclei of the spores of Plasmodiophora are 

 formed by karyogamy (Arb. aus den kaiserl. Gesundheitsamte, xxii., 1905, p. 396). 



