Zoological Society . 417 



The author, after balancing the arguments of the two theories 

 respecting the classification of this body, gave as his reasons for 

 retaining them on the side of the animal kingdom, the following 

 summary : — 



1st. That while Closterium has a circulation of molecules greatly 

 resembling that of plants, it has also a definite organ, unknown in 

 the vegetable world, in which the active molecules appear to enjoy 

 an independent motion, and the parietes of which appear capable of 

 contracting upon its contents. 



2nd. That the green gelatinous body is contained in a membra- 

 nous envelope, which, while it is elastic, contracts also upon the 

 action of certain re-agents, whose effects cannot be considered 

 purely chemical. 



3rd. The comparison of the supposed ova with cytoblasts and 

 cells of plants, precludes the possibility of our considering them as 

 the latter, while the appearance of a vitelline nucleus, transparent 

 but molecular fluid, a chorion or shell, determines them as animal 

 ova. It was shown to be impossible that these eggs had been de- 

 posited in the empty shell by other infusoria, or that they were the 

 produce of some entozoon. 



4th. That while it was impossible to determine whether the 

 vague motions of Closterium were voluntary or not, yet the idea the 

 author had formed of a suctorial apparatus, forbad his classing them 

 with plants. 



Lastly, in no instance had the action of iodine produced its ordi- 

 nary effects upon starch or vegetable matter, by colouring it violet 

 or blue, although Meyen asserts it did in his trials. 



The author therefore concluded that Closterium must still be 

 retained as an Infusory Animal, although it is more than doubtful 

 whether it ought to rank with the polygastric families. 



ZOOLOGICAL SOCIETY. 



November 26, 1839.— William H. Lloyd, Esq., in the Chair. 



An extensive collection of shells, sponges, &c., presented by J. B. 

 Harvey, Esq., Corr, Memb. Zool. Soc, was exhibited. The specimens 

 contained in this collection are from South Australia, and were prin- 

 cipally collected in Kangaroo Island. 



Prof. Rymer Jones called the attention of the Meeting to certain 

 specimens contained in this collection, and to the sponges in par- 

 ticular, and, having made some observations upon their structure and 

 mode of reproduction, he entered into the question relating to their 

 animal or vegetable nature. 



Ann. Nat. Hist. Vol.5. No. 33. Aug. \SiO. 2g 



