162 NATURAL HISTORY SOCIETY OF DUBLIN. 



powers, under the hallucination that there might he a hope of fortui- 

 tously stumbling upon it unawares ! 



After having, I might almost say, disported themselves in the man- 

 ner described for a period from about twenty-four to thirty- six hours, 

 their locomotive powers began to wane, and their energy and agility to 

 flag ; presently their onward progress hecame gradually slower and 

 slower, and the lobose pseudopodal processes alternated more and more 

 lazily and languidly, until, by degrees becoming more and more inert, 

 they finally one hy one became altogether still. At this point, I greatly 

 regret, my observations upon this marvellous condition also came to an 

 end. Just as they had all or nearly all acquired a rotund protococcoid 

 figure, having heen ohliged to leave them, the slide, upon which they 

 were, became dried up during my ahsence, nor could I find at any other 

 period any more of these Stephanosphserse undergoing this remarkable 

 phase. But, from finding in the bottle whence these were taken numbers 

 of the protococcoid condition, it is probable, had these special examples 

 not been interrupted or thwarted in their development, that they too 

 would have passed from the amcehoid to the protococcoid condition. 



I presume I need not here delay hy urging the now, I helieve, uni- 

 versally acknowledged claims of Stepkanosphsera, and of the remaining 

 Volvo cinacese, to rank in the vegetable kingdom. Their whole affini- 

 ties are with certain algse of the Chlorospermatous class. Hydrodic- 

 tyon utriculatum, an indubitable alga (not found in Ireland), presents, 

 at every step of its history, points in common with Stephanosphaera, and 

 both Hydrodictyon and the Volvocinacese are closely related to Pedias- 

 trese, and to the genus Polyedrium (Nag.), &c, &c. So intimate is this 

 affinity, that I conceive those who would now refer Volvocinacese to 

 the animal kingdom, would be compelled to include Hydrodictyon and 

 Pediastrese in the transfer, and, so far as I could see, by an inevitable 

 sequence, the whole of the Confervoideae (Chlorospermese) likewise ; 

 which, I need hardly remark, would be simply absurd. 



There was a time when locomotion effected by the agency of cilia 

 was regarded as an infusorial or animal characteristic ; now it is well 

 known that very many undoubted vegetables, in some phase of their ex- 

 istence, are provided with these appendages. There was a time when 

 the existence of the so-called " eye-speck" was regarded as a peculiarly 

 animal indication ; it is now well known that the active spores of many 

 undoubted algse possess this red dot ; nay, some unicellular plants, whose 

 whole life seems to be passed in a still condition, very beautifully ex- 

 hibit this characteristic. There was a time when the presence of a 

 " contractile vesicle" was looked upon as an animal characteristic; but 

 this too shows itself in plants; for instance, Gonium. There was a 

 time when contractility, though merely indicating itself by a capacity 

 of altering relative length and breadth, or of taking and recovering an 

 external impression, was regarded as purely an animal mark ; but many 

 vegetable cells (zoospores) possess it. There was a time when the pre- 

 sence of starch was regarded as a strictly vegetable characteristic ; but 

 this product has been found in the animal kingdom; for instance, Amoeba. 



