RECENT LITERATURE OF THE MUSCLES. 305 



In certain situations, e.g., immediately beneath the lining membrane of the 

 ventricles, the cardiac muscular tissue shows a peculiar modification in the form of a 

 network of clear beaded fibres, just visible to the naked eye, which were described by 

 Purkinje, and are known by his name. When examined with the microscope they 

 are seen to be composed of large clear quadrangular cells ; each usually contain 

 two nuclei near the centre, with a little granular protoplasm around the nuclei. At 

 the margin of the cells are columns of transversely striated muscle-substance, which 

 partly surround the cells and appear to join with the muscle-columns of adjacent 

 cells, so as to produce the aspect of an open network of muscular fibres with large 

 cells occupying its meshes. The most probable explanation of this appearance is 

 that these are cells of the muscular tissue the differentiation of which has been 

 arrested at an early stage of their development, and that the cells themselves have 

 continued to grow without any further formation of the cross-striated substance. 



Like the skeletal muscles the heart-muscle is richly supplied with blood-vessels. 

 The muscular tissue differs, however, from that of ordinary skeletal muscles in the 

 large supply of lymphatic vessels with which it is provided. The lymphatics, in 

 fact, occupy almost all the interstices of the muscular network, so that the muscular 

 substance is like a sponge, the meshes of which are occupied by lymph. The nerves 

 which are supplied to the cardiac fibres are all non-medullated near their termina- 

 tions. Their manner of ending will be afterwards considered. 



RECENT LITERATURE OF THE MUSCLES. 



Babinski, J., Des modifications que presentent les muscles a la suite de la section des nerfs qui 

 s'y rendent, Comptes rendus, t. 98, 1884. 



Ballowitz, E., Fibrilldre Structur und Contractilitdt, Pflliger's Archiv, Bel. xlvi., 1889. 



Barfurth., D., Die Ruckbilduny des FroscMarvenschwanzes und die soyenannten Sarkoplasten, 

 Archiv f. mikrosk. Anatomic, Bd. xxix., 1887. 



Bremer, L., Ueber die Muskelspindeln nebst Bemerkungen uber Structur, Ntubildung und Inner- 

 vation der q tier gestreif ten Muskelfaser, Arch. f. mikr. Anat., Bd. xxii., 1883. 



Busachi, T., Ueber die Regeneration der glatten Muskeln, Medic. Centrabl. , 1887. 



Butschli u. Schewiakoff, Ueber den feineren Bau der quergestreiften Muskeln bei Arthropoden, 

 Biol. Centralbl., Feb., 1891. 



Ciaccio, Q-. V., Sur I'anatomie microscopique des muscles qui servent a mouvoir les ailes des 

 insectes, Archives ital. de biologic, t. ii., 1882 ; DelV anatomia minuta di quei muscoli die negl'insetti 

 muovono le ali, Memorie della reale accad. delle scienze di Bologna, Serie IV., t. viii., 1887. 



Emery, Sur la structure des fibres musculaires strides de quelques vertebras, Archives ital. de biol., 

 ii., 1882. 



Exner, S., Ueber optische Eigenschaften lebender Muskelfasern, Pfliiger's Archiv, Bd. lx., 1887. 



Fantino, G., Sur les alterations du myocarde apres la section des nerfs extracardiaques, Archives 

 italiennes de biologic, x., 1888. 



Felix, W. , Die Ldnge der Muskelfaser bei dem Menschen und einigen Sdugethieren, Festschrift f. 

 A. v. Kolliker, 1887 ; Theilungserscheinungen an quergestreiften Muskeln menscklicher Embryonen, 

 Anatom. Anzeiger, 1888 ; Ueber Wachsthum der quergestreiften Musculatur nach Beobachtungen am 

 Menschen, Zeitschr. f. wiss. Zool., Bd. xlviii., 1889. 



Franque, O. v. , Beitr. z. Kenntniss der Muskelknospen, Wurzburg Verhandl., 1890. 



Gage, S. P., Form, endings, and relations of striated muscular fibres in the muscles of minute 

 animals (mouse, shreiv, bat and English sparrow), The Microscope, Detroit, 1888. 



Gehuchten, A. van, Etude sur la structure intime de la cellule musculaire stride, La Cellule, t. 

 ii., 1886, and t. iv., 1888 ; L Les noyaux musculaires de la grenouille adulte, Anat. Anz. iv., 1888; 

 Cellules musculaires strides ramifiees et anastomosees, Anat. Anz., Suppl. Heft, 1889. 



Goldenburg 1 , B., Untersuckungen uber die Grossenverhaltnisse der Muskelfasern des normalen, 

 sowie des atrophischen und des hypertrophischen Herzens des Menschen, Dissert., Dorpat, 1885. 



Griitzner, P., Zur Anatomie und Physiologic der quergestreiften Muskeln, Recueil Zoologique 

 Suisse, 1884. 



Haswell,"W. A. , A comparative study of striated muscle, Quart. Journ. of Microsc. Science, xxx., 1889. 



Haycraft, J. B. , On the minute structure of striped muscle, with special allusion to a new met/iod 

 of investigation, by means of "impressions" stamped in collodion, Proc. Roy. Soc., vol. 49, 189 1. 2 



1 The student is referred to these articles for the older Bibliography of the subject. 



2 Haycraft has endeavoured to show that the cross-markings upon a muscle-fibre are nothing but 

 the optical effect of varicosities of the component fibrils, since impressions of muscle in collodion repro- 

 duce most of the cross-striated appearances. But this fact is entirely insufficient to prove the point, for 

 it is clear that a difference in consistence of the different parts of the muscle-element would alone lead to 

 the reproduction by the impression -method, and in view of the entirely different optical and chemical 

 properties of the different parts of the muscle-element, such a position is quite untenable. 



