336 Occurrence of Confervee on Gold-fish. 



have seen it with its contents hanging together from a rup- 

 ture in its walls. 



Proceeding to observe the changes which the spore itself 

 undergoes, I detected lying here and there, among the at- 

 tached extremities of the primary filaments, groups of spores 

 corresponding in numbers and characters to those which I 

 had seen escaping from the spore-cases. 



The most careful examination revealed no nuclei or con- 

 tents of any kind in these transparent vesicles, which in this 

 their perfect state were about 2 oVo^^ °^ ^"^ ^"^^^ ^" diameter. 



The first step in the development m as an opacity of tlie 

 spore, due to the development of granules similar to those 

 which have been so often mentioned. 



2. The vesicle elongates. 



3. It appears double ; that is, two-celled. 



4. Both cells elongate and acquire additional cells at the 

 extremity, which is known to be the terminal extremity by 

 secondary filaments appearing on it. 



A sufficient number of examples could not be met with to 

 trace these changes with greater minuteness, so that certain 

 circumstances which I was anxious to detect, and to which I 

 shall allude immediately, escaped observation. 



I may state that I met with one example of the incipient 

 development of a dichotomous primary filament. It occurred 

 at the point of attachment of a fertile articulation, and might 

 therefore be considered, in some measure, as one mode in 

 which the primary filament or axis of the individual is con- 

 tinued, when its elongation would otherwise have been inter- 

 rupted by the development of the former terminal articulation 

 into a spore-case. 



This incipient lateral filament appeared as a conical projec- 

 tion from the side of the upper extremity of the penultimate 

 articulation. I could not make out the existence of a dia- 

 phragm at the base of the little cone ; as however it, as well as 

 the penultimate articulation, was full of granular matter, a 

 diaphragm might have existed, although I did not observe it. 

 A clear vesicle, such as I have formerly described, was situated 

 at the terminal extremity of the penultimate articulation ; but 

 whether it belonged to the new articulation or to the old one, 

 I could not determine. 



I have been unable to determine in a satisfactory manner 

 the exact nature of the clear vesicle which is found in each of 

 the articulations. It may be the nucleus of the original cell 

 of the articulation ; but if it be so, it must be considered as a 

 barren nucleus ; having increased in size proportional to its 

 cell, having lost the normal appearance of a nucleus, and 



