better knoion as the Coccolitli. 185 



eminent naturalist had first formed, in 1858 {op. cit.), viz. that 

 it was a unicellular Alga, I still further became convinced of 

 this by hnding it abundantly in the alimentary canal of the 

 large Ascidian^ {Ascidia arachnoidea, Forbes & Hanley) which 

 is thrown ashore here during storms. 



Referring, then, again to Prof. Huxley's ])aper and accu- 

 rate illustrations of coccoliths, I observed that he came to the 

 two following conclusions, viz. : — 



(1) " That they are not independent organisms, but that 

 they stand in the same relation to the protoplasm of Bathyhins 

 as the spicula of Sponges or of E-adiolaria do to the soft parts 

 of those animals;" and (2) "that the coccospheres are from 

 the first independent structures, comparable to the wheel-like 

 spicula associated in the wall of the ^ seeds ' of Spongilla, 

 and perhaps enclosing a mass of protoplasm [of Bathyhius] 

 destined for reproductive purposes " (/. c. pp. 210 & 211). 



Now, finding the coccolitli so abundant throughout the La- 

 minarian zone here that hardly any object can be examined mi- 

 croscopically without its presence in greater or smaller numbers, 

 also that in the alimentary canal of the Ascidian just men- 

 tioned it is more abundant than the frustules of Diatomaceaa 

 or the remains of any other organism of this kind, while it is 

 in a more or less fragmental condition, indicative of the effect 

 of digestion, I could not help feeling still more in favour of 

 its being an organized cell. 



Hence I subjected a portion of the contents of the alimen- 

 tary canal of Ascidia arachnoidea^ in which there were many 

 entire as well as fractured coccoliths, to the following chemical 

 tests, watching at the same time their effect, under a glass 

 cover, with the microscope. 



(1) Solution of iodine in iodide of potassium produced no vi- 

 sible alteration. (2) Acetic acid, being added in sufficient quan- 

 tity to more than neutralize the former, caused the calcareous 

 cell of the coccolitli to become dissolved, leaving a granular disk 

 of protoplasm, in the centre of which was the original oval 

 transparent area containing one or more granules, as the case 

 might be : all the granules were of a yellowish colour, both 

 in the disk and transparent area ; and as the cell became dis- 

 solved away, so the greenish tint, which is owing to the pre- 

 sence of the calcareous material, also disappeared ; but still no 

 further visible change occuiTcd. (3) The sol. iodine 6i.c. was 

 again let in (by the aid of a piece of bibulous paper which was 

 placed on the opposite side of the cover) ; but the granules &c. 

 still remained unaltered, and did not present the blue tint in- 

 dicative of starch. (4) Finally, the acetic acid was reapplied, 

 without further change ; and after the aqueous contents had 



