288 'PROCEEDINGS OF SOCIETIES. 



inflated in a globose manner ; at each free end of the so united 

 Closteria there was the usual clear space with moving granules, 

 but at the fused ends there was but one such space, and this 

 occupying the centre of the globose inflation. This outre speci- 

 men ofl"ered a curious example of apparently the same mons- 

 trosity which is occasionally seen in various species, especially of 

 Cosmarium and Euastrum, but is seemingly more rare in the 

 present genus. 



Mr. Archer observed that no instance similar to that drawn 

 attention to by Mr. Crowe had ever been met with by himself in 

 the genus Closterium, and he knew of but one figure of a similar 

 case, that given by Eeinsch in his ' Morphologische Auatomische 

 iind Physiologische Pragmente, 'pi. ii, fig. 7, which, opportunely 

 enough, he happened to have brought down with him. In that 

 instance, however, the middle or intervening inflation had not 

 become at all so largely expanded as in that drawn attention to 

 by Mr. Crowe. But Eeinsch's interpretation of this singularity 

 did not apparently agree with that which Mr. Archer thought to be 

 the true one, for that author seemed to regard this as an instance 

 of normal self-division, and as simply proving that in Closterium 

 this followed the same law as in Cosmarium and other desmidian 

 genera, whereas it appeared to Mr. Archer to be but an instance 

 of abnormal growth, quite comparable to that not uncommon in 

 other genera, where no intervening septum is formed between the 

 new young half-cells, and hence the new and old growth forms 

 but one uninterrupted cavity, the central portion being often dis- 

 torted and misshapen. So far from this phenomenon, depicted 

 in Eeinsch's figure and that of Mr. Crowe, representing normal 

 growth, it is easy to find in a fresh gathering of Closteria many 

 examples of self-division, which accords quite with that of a Cos- 

 marium or Euastrum in essential points, mainly differing, indeed, 

 in the fact that the growth of the new half-cell in Closterium is, 

 for the most part, perfected after separation, in place of remain- 

 ing attached until the new half-cells (or segments) have acquii-ed 

 nearly or wholly the size and character of the old ones. The phe- 

 nomenon in Closterium represented in the figure alluded to seemed 

 to be quite the same as that illustrated in other genera (Cos- 

 marium and Staurastrum) by other figures on the same plate 

 (1. c, pi. ii, figs. 4, 5, 6), and well explained at p. 37 (1. c). It 

 seems evident that, if a double wall is not formed at the very 

 commencement of vegetative growth, there must be then a fusion 

 or soldering together of the seginents, just such as Eeinsch's 

 Closterium and that now exhibited evince. 



Dr. E. Perceval Wright exhibited thespicula in siiu,and explained 

 the character of certain Corticate sponges met with by him in 

 Seychelles ; but as he intends to present tbe Club with a con- 

 nected detail of his observations on this group of sponges, it would 

 be premature to enlarge upon them here. 



Dr. Dickson exhibited longitudinal sections from the stem of a 

 species of Smilax, showing scalariforiu ducts, forming a very 



