of the Chalk. 97 



unlike some vegetable tissues (see fig. 7. PL VIII.) . The decep- 

 tiveness of appearances thus caused has been already fully 

 pointed out. This integument was very possibly muscular. 



The fibres of the roots, like those of the body, all anastomose 

 together. They do not overlie nor entwine. 



When it is remembered that sulphuret of iron is deposited 

 more or less on every fibre that has been actually preserved, it 

 will be obvious that it is impossible to ascertain the exact size of 

 the recent fibre. I have however frequently observed the better- 

 preserved fibre to be less than the 4000th of an inch in diameter 

 in its present condition ; much appears about the 2000th of an 

 inch ; and the coarser and less perfectly preserved rarely exceeds 

 the thousandth of an inch in its present condition. The fibre is 

 single and solid (never fistular). It is generally found both in 

 flint and chalk reduced, more or less, to its ultimate granular tex- 

 ture, in which case it resembles the granular texture of other 

 animal fibre. This granular texture is finer, even in its present 

 condition, than that of the recent Actinia. 



The description of another most interesting point which I have 

 discovered in connexion with these animals — the ovarian cells — 

 will more properly come under the next division of the subject, 

 when the natural affinities of the animal are considered. I con- 

 tent myself for the present with stating the fact of the discovery 

 and clear establishment of these ovarian cells, a fact which cannot 

 but be felt by every naturalist to be of the very highest import- 

 ance, both in relation to the individual beings themselves and as 

 an aid in determining their natural affinities (see PI. VIII. fig. 3). 



And now, having thus too imperfectly described the intimate 

 structure of these animals, so elegant and graceful even in their 

 external forms, I hope that I shall be felt not to have expressed 

 a too strong sense of the exquisite beauty of that structure. I 

 have searched in vain amid zoophytic forms for any structure 

 that may compare with that of the Ventriculidse in delicacy, 

 beauty, and obvious adaptation. The pride of man may call all 

 those beings who differ most from him in structure the "lower 

 animals f but I would ask, Where can be found an organization 

 more complex or more exquisitely delicate, or where adaptation 

 more perfect, than is displayed in the structure of the Ventri- 

 culidse ? Where can we find a structure affording more conclu- 

 sive evidence of the all-prevalence of those laws of Unity and 

 Design which it is the grateful task of the naturalist to de- 

 velope, and of which his inquiries, the further they extend, do 

 but unfold a wider field of illustrations for man to study and 

 admire ? 



[To be continued.] 



