280 REMAK, ON THE EMBRYOLOGICAL 



truth is, as I have elsewhere shown, that together with 

 and at the cost of the granular protoplasm, a homogeneous, 

 continuous soft substance arises, wliich acquires on the surface 

 a system of fine transverse i'urrows, in conse(juence of the first 

 movement of the animal.^ In the vertebrata, after the for- 

 mation of the sarcous cylinders within the sarcolemma, no 

 vestige is left of the grannies of the protoplasm. The series 

 of fatty granules, which may be observed in mature animals 

 betAveen the so termed fibrillse, and which are very abundant 

 in the muscles of fatted carp and pigs, are of a later and 

 pathological origin, and represent the first indication of the 

 pathological condition, which in man has been termed " fatty 

 degeneration.'^ These granular deposits are seen mostly in 

 the neighbourhood of the nuclei, and particularly at their 

 extremities, and thence they come to present a fusiform 

 appearance, to which, without any necessity, the name of 

 muscle -corpuscle has been given. In place of recognising 

 this truth, and describing the phenomenon in question as 

 unessential and unimportant as it really is, Schultze raises 

 the question whether the so-termed muscle-corpuscles might 

 not lay claim to the title of " cells." 



With a view of solving this query, Schultze proceeds to con- 

 sider the primordial type of cells, viz., the embryonic cells, 

 and finds that they consist of a viscous protoplasm, crowded 

 Avith granules and a nucleus. The internal layer, it is said, is 

 often formed merely of the homogeneous matrix, " but these 

 cells are never furnished with a membrane chemically distinct 

 from the protoplasm." He then declares that '' I had given 

 myself great trouble to demonstrate the presence of a membrane 

 in the segmentation cells of the frog." I have also succeeded, 

 by means of hardening agents, in raising from the segmenta- 

 tion-globules a transparent layer, which I have regarded as a 

 naerabrane chemically distinct from the protoplasm. Even 

 Schultze himself has thought that ''he -was able to raise a simi- 

 lar membranous layer in Peiromyzon, but more recent research 

 has made him seriously doubt the value of the proof aflForded 

 by this method." Were a " chemically distinct" membrane 

 really present, it would necessarily be capable of demonstration 

 by other means. The cause of the deception depends upon 

 the condition of the protoplasm ; in the hyaline substance, 

 '' the granules are absent in the outermost layer," and when 

 this layer is distended, it presents the appearance of a mem- 

 brane. However certain it may be that the external layer of 

 protoplasm may " at any time be transformed into an ex- 



* "Ueber den Bau unci die Zusammeuziclmng der Muskelfasern.' 

 * Monsetsb. d. d. Wiener Akadernie.' 



