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of the ontogenetic development of the musele-fibres always brought 
me back to the old, time-honoured theory. 
But I must add immediately that even for the adult muscle-fibres 
the study of the admirable preparations made by Miss Dr. M. van Hrr- 
WERDEN, Which she had the kindness to show me in my laboratory, 
left no doubt as to the truth of her observations against the state- 
ments made by Scuuttze and his pupils. Both the sharply-stained 
extremely thin sections and the preparations in which the muscular 
fiber was digested by means of a trypsine-solution '), the sarcolemma 
and the tendonfibres however left intact, demonstrated very clearly 
the discontinuity of the elements in question. 
It seems to me, that the solution of this problem is given by the 
ontogenie development of the musecle-fibres, and even here the 
minute details are not always sufficiently clear to give a definite 
account of the development of the muscle-cells in relation to their 
mode of attachment to the tendon-fibrillae. 
Splendid material to work with in this direction is given by the 
developing myomeres, the trunkmyotomes of several teleostians, 
and especially in meraenotds the details of the developmental processes 
are shown with the utmost clearness. Of muraenoid eggs and larvae, 
preserved after the best methods, and cut into thin (4—6 «) longitudinal 
and transverse sections, stained with iron-haematoxylin and counter- 
stained by eosine, our laboratory possesses a large collection of 
more than a hundred specimens, and at the hand of this series -of 
preparations I will give here an account of the development of 
the* muscle-fibres of the trunk-myotomes. 
The general development of the trunkmyotomes, the changes in 
form and size, the differentiation of the musele-cells, have been 
described very fully and illustrated by a large number of drawings 
in the inaugural dissertation of Dr. A. Sunier’), so I need not 
enter into these details here. The first evidences of muscular different- 
iation consist of the lengthening of the cells of the myotome, until 
they reach from one end of the myotome, the cranial end, well into 
the mass of cells toward the other end. The nuclei of these cells 
alter their staining reaction and begin to divide amitotically, 
h The opposite results, obtained by SecHuurze in his digesting experiments, are, 
as Dr. vAN HERWERDEN tells me, due to his having used an alkaline solution of 
trypsine and not tlie neutral one, he should have used to leave the collagenous 
fibres intact. , 
2) A. J. L. Sunter. Les premiers stades de Ja différentiation interne du myotome 
et la formation des éléments sclérotomatiques chez les acraniens, les sélaciens, et 
les téléostéens. Inaug. Dis. Groningen. Brill, Leiden 1911. Has been published 
also in the Tijdschrift der Nederl. Dierkundige Vereeniging Jaarg. 1911. 
