ALG.E. 141 



appeared sometimes in but very small quantity, while 

 on other occasions it was to be seen much more 

 abundantly. This appearance and disappearance 

 seeming to be independent of the direct rays of the 

 sun, but probably the result of meterological in- 

 fluences. 



Under the microscope it was found to consist of 

 exceedingly minute, simple, moniliform threads, with 

 the globules composing them of uniform diameter, 

 and the threads themselves variously but elegantly 

 curved and grouped together, without order in a 

 gelatinous matrix. Hence the conclusion that the 

 substance was an alga, and very near to Anabcena, 

 similar to the alga of Ballydrain Lake, which Pro- 

 fessor Allman called TricJionnns spiralis, and the 

 present one Trichorums incurvus, but both now re- 

 ferred to Aiiabcuna flos-aquce. 



It is remarked that Bory Saint-Vincent was so 

 impressed with a belief in their animal nature that 

 he removed the genus Anabccna from the vegetable 

 kingdom. The peculiar motion of reptation which 

 he describes them as possessing, and which he com- 

 pares to the crawling of worms, would appear to 

 have been the chief grounds on which he assumed 

 their animality. No such motion was detected in 

 the species of Ballydrain Lake, or the Grand Canal 

 Docks. When a large mass of the latter was placed 

 in a limited quantity of water, decomposition soon 

 set in, the green colour becoming duller, and finally 

 assumed a dirty, ferruginous hue. A disagreeable 

 odour was at the same time exhaled, but this odour 

 was altogether different from that of decomposing 



