8 Mr. H. J. Cai-ter on Eudorina elegans. 



V, stellatiis, where it might have taken place from some of the 

 spores not having been impregnated, and thus not getting the 

 spinose capsule. Out of some hundreds of specimens of V. (jlo- 

 hator I have only met with two instances in which the daughter- 

 cells were undergoing an irregular kind of duplicative subdivi- 

 sion something like that of V. stellatus ; and these were in two 

 specimens, each containing a single generation, where the latter 

 had been disturbed in their development and partly destroyed 

 by the presence of Rotatoria, which thus seemed to account for 

 these abnormal forms. Nor have I ever seen the impregnated 

 spores pass into the " matrass-form " mentioned by Dr. Cohn 



Eudorhia elegans, Ehr. 



My first observations on Eudorina elegans this year were made 

 at the commencement of June, after which the deluging rains 

 of the monsoon commenced, and arrested everything in the way 

 of active algal development until August, when the showers be- 

 coming less frequent and less powerful, and the sun reappearing 

 for longer periods, I found Eudorina again in several places, 

 and have thus been enabled to clear up, add to, and correct 

 respectively what I have already stated of this organism in 

 my paper on its fecundation. Had I, however, known that I 

 should have had this opportunity again, after so short an inter- 

 val, I should have deferred the publication of that paper until 

 the present time, in order that these addenda might not have 

 been required. 



In my description of the development of Eudorina^ I have 

 alluded to the question how, in the " second stage,^' the sixteen 

 additional cells get their cilia through the external envelope, and 

 have inferred that the sixteen new cells either make channels 

 for themselves, or the group comes forth from its parent-cell 

 with the thirty-two cells fully formed. Later observations have 

 shown me that the latter is the case, and that this part of the 

 development takes place in the manner already suggested in the 

 development of Volvox ; therefore there is one form of Eudorina 

 elegans consisting of sixteen cells and another of thirty-two 

 cells, and the two do not pass into each other. This point has 

 been determined by my having found the two varieties in two 

 separate tanks about 200 yards apart, and not mixed in cither 

 tank, although each tank swarmed with its respective variety. 

 Thus, in one, all the Eudorina in the "first stage ■'^ contained 

 thirty- two cells, and again passed directly into the form of thirty- 

 two groups with thirty-two cells in each group ; while in the 

 other tank, all in the first stage contained sixteen cells, and they 



* Aunals, ser. 3. vol. ii. p. 237. 



