336 



Occurrence of Conferva on Gold-fish* 



have seen it with its eontents 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 1 

 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 (jo(J tn °f an mcn in diameter. 



The first step in the development was an opacity of the 

 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 



