112 OOCTSTIS AND EREMOSPH.ERA, 



characteristic form or size. Indeed, as a general rule, there may 

 be said to be only three types — the globose or subglobose, the 

 oval or oblong, and the tuberculate. It is the free vegetative 

 cell, rather than the mother-cell or autospore, that is distinctive 

 of the type. 



Chloroplasts. — In the following notes, many variations will be 

 found, which are established on differences in the chloroplasts. 

 These should not be looked upon as distinct varieties, but as 

 forms brought about by development. There seems to be no 

 doubt that the small, discoid chloroplasts are produced from the 

 simple, parietal lamina by a process of division into 2, 4, 8, 16, 

 etc. While it is true that the two forms of chloroplast, the 

 discoid and the laminar, are rarely found in the same species, 

 this is because they ai'e the products of different environments, 

 the former being characteristic of swamp-forms, and the latter of 

 plankton- or pond-life. It is probable that both are found in 

 0. Ncigelii, which seems to occupy an intermediate position. 



2. Polymorphism of EremospJuera. 



This was first demonstrated by Chodat, in Bot. Zeitung, liii., 

 l895(Ueber die Entwickelung der Eretnospfucra viridis De By.), 

 where a numbei- of polymorphic forms and reduction-forms, 

 Glceocysf/is-, Falmella-, and C entrosphcer a-iMndiiiomi are repro- 

 duced.* The most distinctive of the polymorphic forms, I.e., 

 T. v., f. 10, will be found described and figured in my notes on the 

 species. 



Physiological. — The Palmella- and Centrosphfera-st'AteH, I have 

 not yet met with, nor even the Glwocystis-iorma till just lately. 

 These last were present, however, in a gathering from Woy Woy 

 kindly sent to me by Mr. A. H. S. Lucas. Some of them will 

 be found in Text-fig. 2. They measure from 80-100/* long, the 

 breadth being somewhat less. The envelopes, of which there may 



* This important contribution is a study in itself; there are too many 

 points brought forward for me to do more than touch upon one lieie and 

 there; (jut of a large number of interesting figures also, I can only repro- 

 duce one or two in suppcjit or illustration of my own observations. 



