PROTOCOCCUS PLUVIALIS. 519 



globular mass, which, is probably contained in a second 

 cell. This was evident, however, in only one case. 



As more intimate constituents of the contents, both in 

 the still and in the motile form, numerous more minute 

 spherules are to be considered. The red formative 

 material is to be referred to the sphere of fructification, 

 the green to that of vegetation. Consequently the green 

 spherules in Hamatococcus must be regarded as fferm 

 granules, ox gonidia, which, when larger and internally 

 organised by a cell nucleus, become green gemmules. 

 When these gemmules, in the form just described, escape 

 from the mother-cell, they resemble the innumerable 

 dependent forms commonly associated under Protococcus 

 Monas ; they exhibit an instance of retrograde meta- 

 morphosis, producing a succession of similar organisms, 

 which, shooting out in succession in a longitudinal direc- 

 tion, constitute confervoid filamentous forms, or, sprouting 

 out, expand into Ulva-like growths. Amongst the latter, 

 one is very remarkable, foliaceous, of a quadrangular 

 figure, consisting of many cells, which, like a simple 

 Hcematococcus cell, is carmine red in the centre and 

 green towards the margin. 



The green gemmules, however, are capable of pro- 

 gressive development, destined to reproduce the Hmnato- 

 coccus at once, when, for instance, the individual to which 

 they belong possesses sufficient red formative mucus 

 for its penetration and fructification. This is apparent 

 from the circumstance that the two-coloured, still forms 

 which are entirely filled with red and green gemmules, 

 in process of time become altogether red. And in this 

 case the red coloration gradually extends from the central 

 nucleus, as its original seat, towards the periphery, 

 whilst in the retrograde metamorphosis the red colora- 

 tion of the globules proceeds from without to within. 



In whatever way the spores formed of this red sub- 

 stance escape, they develop themselves, and at an un- 

 favorable time of year and dormant condition of vitality, 

 float, in flocculent aggregations, on the surface of the 



