420 Scientific Intelligence, — Physiology and Zoology, 



which assume a more or less globular, or elliptical appearance resem- 

 bling cells. Their interior is dark, from a great increase of red co- 

 louring matter, which accumulates around a pellucid and colourless 

 point, corresponding in situation to that of the central part of nu- 

 clei in other cases; and so completely do the corpuscles fill their 

 vessels, that the fluid portion of the blood is excluded, and the cor- 

 puscles are compressed into polyhedral forms. This condition of tlio 

 blood-corpuscles during vitalturgescence of the vessels theauthorthinks 

 deserving of consideration, in connexion with many of the phenomena 

 attending local accumulations of blood, both in health and in disease ; 

 and more especially with reference to increased pulsation, the exuda- 

 tion of colourless fluid, and the heat and redness of inflamed parts. 

 According to the views of the author, the formation and nourishment 

 of organs is not effected merely by the fluid portion of the blood, 

 for he has discovered that the cells which he shewed in his " Third 

 Series of Researches in Embryology" form the chorion, are altered 

 blood-corpuscles ; and he has farther found that muscular fibre (that 

 is, the future muscle-cylinder, not the fibril) is formed by the coa- 

 lescence of cells, which also are derived from corpuscles of the blood. 

 Ho has seen and figured every stage of transition, from the unaltered 

 blood- corpuscle to the branched cells forming the chorion, on the one 

 hand, and to the elliptical or oblong muscle-cells, on the other. Th j 

 colour is not changed, except that the bood-corpuscles, when passing 

 into cells for the formation of muscle, become of a much deeper red. 

 There seems to occur in these an increase of red colouring matter. 

 Valentin, in describing the mode of the formation of muscle, had 

 stated that globules approach one another and coalesce to form thready, 

 which in many places have the appearance of a necklace, but subse- 

 quently lose the traces of division, and become cylinders. Schwann 

 had conjectured that the globules just referred to — as having been 

 observed by Valentin — are cells, and that these cells coalesce to 

 form a secondary cell, that is, the muscle- cylinder. The author 

 confirms the observations of Valentin and the conjectures of Schwann, 

 with the addition, that the globules coalescing to form the muscle - 

 cylinder are blood-corpuscles which have become cells. The fibrils 

 appear to be subsequently formed within the cylinder, which thus 

 becomes the muscular fasciculus. The medullary portion of tlie 

 cylinder appears to be composed of the pellucid objects, one of which 

 is contained within each altered blood- corpuscle. Some of the.>ie 

 pellucid objects, however, continue to occupy a peripheral situation. 

 The author thinks it is not probable that muscular fibre and the 

 chorion are the only tissues formed by the corpuscles of the blood ; 

 he is disposed rather to inquire, hov/ many are the tissues whicii 

 they do not form ? Nerves, for instance, are known to arise very 

 much in the same manner as muscle-cylinders ; and epithelium-cells 

 sometimes present appearances which have almost suggested to 

 the author the idea that they were altered corpuyeles ol' the IJood. 

 Schwann had previously shewn, that *' for all the cWnmntaiy parts 



