18 Transactions of the Society. 



gelatinous frond always presents a transparent border or peripheral 

 stratum without gonidia, and that there is no Hmiting membrane. 

 In the winter, Heufrey saw the gelatinous masses becoming brown, 

 swelling up, and sinking in flocculent clouds. " They appear," he 

 states, '' to become half dissolved, and to allow the green cells to 

 become free." " Perhaps these reproduce the fronds in the next 

 season. No zoospores were ever detected," 



In the sixth volume of the ' Quarterly Journal of Microscopical 

 Science,' Mr. Fred. Currey, P.R.S., Sec. Linnean Society, notices 

 Clathrocysiis fernginosa, and the presence of secondary cells in large 

 ones (in gonidia). He observed the presence of numerous Spirilla 

 on most of the fronds, but he does not distinguish or delineate the 

 hyaline external layer (page 215). 



During a prolonged examination of specimens which were not 

 exposed to unusual heat or pressure, I had, for some hours, the 

 opportunity of watching them actively increasing, but not after the 

 fashion described by Henfrey. 



The fronds were about ^h iiich in diameter, showed the delicate 

 investing hyaline coat ; and the gonidia, tolerably numerous, were 

 distinctly distant from one another, those of the periphery pro- 

 jecting slightly beyond the symmetrical curves of the outside, but 

 being, of course, covered by the hyaline substance. Keflected light 

 gave the usual intense green colour, which was, of course, lost to 

 transmitted light. 



This, under the use of a Zeiss's -|-inch focus object-glass, 

 exposed several interesting structures. The hyaline, perfect in 

 some instances, had extremely delicate dark lines placed radially 

 in others, and its extent was considerable. The absence of any 

 hollow within the fronds was evident, and their matrix was glairy 

 and homogeneous. The gonidia, elliptical in outline, had always 

 one small but very refractive spot, and if two were present, a 

 delicate line separated them. Very few of the fronds presented 

 ragged edges, or were deformed. 



Minute after minute, whilst using a power of 40 diameters, 

 the constriction of several fronds in their midst was observed, and 

 then, very suddenly, they separated into two portions ; each part 

 immediately assuming a globular form. More than one fission was 

 not observed in any frond. 



One of the most marked characteristics of the assemblage of 

 fronds is that the hyaline coat keeps them separate. They cannot 

 approach closely. Hence, when the fissiparous division occurred, 

 there was a general pushing about, for the separation was active 

 and not passive, and each half retained an irregularly disposed 

 hyaline which soon became equally distributed. 



On using a higher magnifying power, this relation of the 

 hyaline investment could be well seen. After a while this fissiparity 



