CLARKE, ON STRIPED MUSCULAR FIBRE, 5 
ing of the origin of the muscular cylinders, he says— 
“J’avoue que la théorie cellulaire ne me rend pas bien 
compte de leur premiére formation, et je n’ai pas pu con- 
firmir leur mode de développement par alignement et fusion 
de globules, mode indiqué par plusieurs physiologistes dis- 
tingués.”* According to him, the first traces of the mus- 
cular fibres make their appearance as fusiform, somewhat 
oval, cylindrical, or irregular corpuscles or cells, which he 
ealls the myogenic bodies, and in which certain indications 
of longitudinal striz are already observable; (‘‘ corpuscules 
fusiformes, ovoides ou irréguliers ;” “corps ou cellules myo- 
géniques ;” ‘‘ espéces de longues cellules irreguliérs”’). He 
confesses, however, that he was unable, by direct observa- 
tions, to determine the mode of origin of these bodies— 
“dans Poiseau, comme dans les autres vertébrés, la premiére 
origine des cylindres musculaires ne peut pas encore étre 
précisée par l’observation directe.”+ It seemed to him that 
they were formed by a coalescence of all sorts of pieces, and 
that the nuclei within them were only accidentally inclosed.t 
It is evident that the “corps ou cellules myogéniques” of 
Lebert correspond to the bodies which I have described and 
represented as appearing in the chick between the sixth and 
seventh day of incubation (see Pl. XI, fig. 9, c, d,e, f); but of 
their mode of origin, as already shown, he was unacquainted. 
Neither does he make any mention of the smaller fibres which 
are formed at an earlier period, as I have already described. 
In 1854 a paper, by Mr. Savory, of London, “ On the 
Development of Striated Muscular Fibre in Mammalia,” 
was read before the Royal Society, and in 1855 was pub- 
lished in Part II of the ‘ Phil. Transactions.’ The results of 
these investigations are completely at variance with the cell 
theory of Schwann. The following is a brief statement of 
the principal facts connected with the plan of development. 
The first stage consists of the aggregation and adhesion of 
the free cytoblasts or nuclei into clusters, and their mvest- 
ment by blastema to form elongated masses, which are irre- 
gularly cylindrical or somewhat flattened. The nuclei thus 
ageregated next fall into a single row, while the surrounding 
substance at the same time grows more transparent, aud is 
arranged in the form of two bands, which border the fibre, 
and increase in thickness by the addition of fresh blastema to 
their external surface. The fibres next begin to lengthen, 
while their nuclei part from each other, and as the distances 
* © Annal. des Sciences nat.,’ 1849, p. 352. 
+ Ibid. 
+ Ibid, p. 377. 
