50 QUARTERLY CHRONICLE. 



forthcoming volume (in the Soc. de Phys. and Hist. Nat. de 

 Geneve) promises to be a most vahiable and important work, 

 perhaps exceeding in vahie, if that be possible, his former 

 essays on the Ohgochoeta, Development, &c. 



Boston Society of Natural History (America). — " On the Spon- 

 gice CUiatce as Ivfusoria Flagellata ; or, Obstrvations on the 

 Structure, Animality and Relationship of Leucosolenia botry- 

 oides, Bowerbank, by H. James-Clark, A.B., B.S. We have 

 already had occasion to notice a portion of this memoir, 

 which appeared a few months since, but wish to draw atten- 

 tion to the paper in its complete form, which has a very high 

 interest, and should be carefully read by those interested in 

 the lowest forms of animals. Two plates illustrate the 

 memoir, which are certainly more satisfactory than the white 

 and black outlines which illustrate the author's first series of 

 observations. 



Professor James-Clarke has apjDlied a power of 1200 

 diameters to that form of life which is usually spoken of as a 

 " Monad," in fact, the Monas termo of Ehrenberg. In this 

 very common and minute creature he has demonstrated a 

 mouth, contractile vesicle, and nucleus spot, which has not 

 been recognised by previous observers. By a gradual series 

 of forms he passes from this Monas, which sometimes is free, 

 and sometimes attached by a short stem as are Vorticelli, 

 up to the ciliated sponges, the individual elements of Avhich 

 he most clearly shows may fairly be regarded as Monas-forms. 

 Some forms closely allied to Monas present a projecting cup 

 or calyx surrounding the oval end of the creature, and from 

 within it arises the flagellum. New genera and species 

 presenting this calyx structure, and varying in aggregation 

 from solitary to compound animals of five or six, are described, 

 and these gradually lead on to Leucosolenia, a cilated sponge 

 in which the calyx, flagellum, and mouth are traceable in the 

 cell-like monads embedded in the sponge tissue, which build 

 it up as a colony of compound Actinozoa build up a coral 

 reef. Mr. James-Clark's paper also contains some observa- 

 tions on Dysteria, that very strange flagellate Infusorian 

 first described by Prof. Huxley in this Journal, and a 

 description of a remarkable new form, Heteromastix. The 

 author's conclusions may be accepted so far as they prove a 

 close relationship in elementary structure betAveen the cilated 

 Sponges and flagellate Infusoria, but we do not know that as 

 yet there is any ground for a change in the classification of 

 either group on this account. We have one deficiency to 

 note in Prof James-Clark's treatment of his subject, and that 



