,'544 Dr. (r. G. Wallic.h on the Coccosphere. 



of wliidi a correct risumS is given in my ])aper " On Deep-sea 

 Protozoa " (' ^lonthlj Micr. Journ.' Jan. 1869) — namely, that 

 after a careful and long-continued study of these organisms, 

 whether occurring as free floating inhabitants of the surface- 

 waters of the Indian Ocean and mid-Atlantic, as components 

 of the present deep-sea deposits, in a fossil condition in the 

 post-tertiary earths, or as living organisms in the British 

 Channel, I have never deviated from the opinion that the free 

 coccoli'ths are derived from their parent coccosjyheres. In 

 some deep-sea deposits, as stated by Prof. Huxley, free cocco- 

 liths undoubtedly occur in overwhelming number as compared 

 with the coccos])heres ; but it is equally true that cocco- 

 spheres are, at times, present in great abundance, whereas free 

 coccoUths are comparatively scarce. Coupling these facts 

 with the very important one, that perfect coccosplieres are to 

 be met with of every intermediate size between the ^^qq and 

 j^ of an inch in diameter, I am induced to believe that the 

 ivee coccolifhs are, in every instance^ formed on, or pari passu 

 with, the spheroidal cells on which they rest, their state of 

 attachment to these cells being their normal as well as pristine 

 condition. That they revert at any future stage of their 

 history, after once becoming free, to their original composite 

 state, there is no recorded evidence forthcoming to prove. 

 (In an appended footnote it was stated that " someof the^ree- 

 jloating coccospheres are oblong.^') Lastly, I stated {loc. ait.) 

 (with reference to the " granular zone " which Prof. Hux- 

 ley described as possibly forming a normal portion of the 

 coccolith), that "amongst the immense numbers of cocco- 

 spheres which had been examined both in the recent state and 

 in the preserved though still recent material of the soundings, 

 I had never met with any proof that this zone exists as an in- 

 tegral portion of the structure ; nor had any evidence presented 

 itself" that the "granular zone " is any thing more than an 

 accidental accretion, or that its presence is due to any inherent 

 condition without which the organism would be incomplete. 

 (" On Deep-sea Protozoa," ^ Monthly Micr. Journ.' Jan. 1869, 

 pp. 35 and 36). 



Having thus far shown that there is no reason to suppose 

 that the Coccosphere is a secondary formation, resulting in any 

 way from an " aggregation " of independently developed " coc- 

 coUths^^'' but that the balance of evidence is altogether in 

 favour of the view that the " coccoUths " are normally developed 

 upon, and simultaneously with, their parent coccosphere, I have 

 now to state the grounds on which I base the opinion that 

 the " coccolith " presents none of the characters of a true 

 " cell.'' 



i 



