1854.] 209 



which when mingled produced a deposit of irregular granules, and in every in- 

 stance a regularly crystalline deposit took place within their cells. 

 It is unnecessary to do more than recapitulate the following results. 



1. Cell-w T alls, like animal membranes, exert a physical influence upon the 

 chemical substances held in solution passing through them. This physical in- 

 fluence is capable of altering the arrangement of the molecules of the precipi- 

 tate formed within the cells, so that the precipitate which under ordinary cir- 

 cumstances consists of irregular granules, under the influence of the endosmodic 

 action assumes a regular crystalline form. 



2. The cells of different vegetables, like different animal membranes, change 

 in different manners the arrangement of the molecules of the same substance. 



It may yet be demonstrated, by experiment, that cells in the same plant, 

 having different offices, elaborating different products, may exert a different 

 physical influence upon the same chemical substance. Or, in other words, the 

 crystalline deposit of the same substance, will vary in physical properties with 

 different cells. 



In conclusion we would state that we are still investigating this subject, and 

 hope to be able to substantiate, by numerous experiments, performed under 

 every possible circumstance, all the laws and facts asserted in this brief abstract 

 of experiments. 



Remarks on the question of the identity of Booiherium cavifrons with Ovibos moschatus 



or 0. maximus.. 



By Joseph Leidy, M.D. 



In the Zoology of the voyage of H. M. S. Herald, the author, Sir John 

 Richardson, in speaking of an extinct species of ox, characterized by me under 

 the name of Bootherium cavifrons starts a question, of which I think there is not 

 the least necessity. On page 120 of his excellent work, he remarks, " Dr. Leidy 

 includes no fewer than twelve crania, all more or less mutilated, and dug up in 

 the valley of the Mississippi, in his species named Bootherium cavifrons, to which 

 he refers Dr. Dekay's specimen; and a comparison of his fig. 2, pi. iii. with the 

 same view of the cranium of the musk-ox in pi. iii. of the ' Zoology of the Herald,' 

 leaves no reasonable doubt of the fossil species being quite distinct from the re- 

 cent one. The accessory trochlea? of the occipital condyles are fully developed in 

 the fossil skull, and many other peculiarities of Ovibos may be discerned in the 

 figures, so that Bootherium and Ovibos are evidently very closely allied. A ques- 

 tion now arises whether the dentata above referred to as the foundation of 

 the proposed palaeozoic species Ovibos maximus may not be a relic of Dr. Leidy's 

 cavifrons, and this might, without much risk of mistake, be decided in the affir- 

 mative, were it certain that the Siberian crania mentioned in the ' OssemeLS 

 Fossiles' were identical in speeies with those imbedded in the drifts of the Mis- 

 sissippi ; but as yet the evidence for such an extension of the ancient range of 

 cavifrons is wanting. The size of Dr. Leidy's specimen of cavifrons does not 

 exceed that of the skull of an aged musk bull, and the dentata of maximus is of 

 corresponding dimensions. If the discovery of a dentata of the musk-ox type, 

 and of suitable size, in the valley of the Mississippi, should hereafter fully 

 establish the identity of cavifrons with maximus, it may be necessary to ascertain 

 which of the two appellations was first made public." 



That Bootherium is closely allied to Ovibos, as declared in my " Memoir on the 

 Extinct Species of American Ox," page 12, there is no doubt ; but that the two 

 genera are distinct I think is proved by the former possessing an important 

 character, which does not exist in the latter nor in ar.y other genus of Bovidae. The 

 character to which I allude is the large lachrymal fossa? cr larmiers situated in 

 front of the orbits, as in the Cervidae, and which are represented in fig. 1, pis. 

 iv., v., of the memoir above referred to, in both species of Bootherium. 



" That the Siberian crania mentioned in the ' Ossemens Fossiles ' " are not 

 ,' identical in species with those embedded in the drifts of the Mississipj i," I 



