94 GENERAL ANATOMY OF THE TISSUES. 



fossilis, around the poison gland of Snakes, and in the contractile 

 organ of the pharynx of the Carp ; in the skin of Mammalia, 

 Birds, Snakes, and tailless Batrachians (so-called cutaneous 

 muscles), in the tactile hairs of mammals, in the lymph hearts of 

 many Birds and Amphibia ; in the auriculo-ventricular valve of 

 the right side in Birds, and the Ornithorhynchus ; upon the vena 

 cava inferior of the Seal, close above the diaphragm ; in the 

 interior of the eye of Birds ; and round Cowper's and the anal 

 glands of mammals. In the Invertebrata, as we have men- 

 tioned, all the muscles belong to this category, whether they 

 be transversely striated or not ; and they are found, therefore, in 

 the heart, the intestine, the genitalia, and often clearly striated. 



The anastomosis of the primitive bundles of the muscles, 

 with which Leeuwenhoek was already acquainted, 1 and which I 

 rediscovered in the heart of the frog, has now been seen in 

 many places, and appears to be constant in the hearts of the 

 lymph and blood-vascular systems of all animals, and in the 

 muscles of the Invertebrata, especially those of the vegetative 

 and generative organs (Hessling, Leydig). Simple arborescent 

 branchings of muscular fibres, which Corti and I noticed in the 

 tongue of the frog, are on the other hand rare, and have been 

 seen elsewhere onlv in Ariemia salina, and in the oral and 

 anal discs of Piscicola (Leydig).] 2 



Literature. — W. Bowman, article Muscle and Muscular 

 Motion, in Todd's ' Cyclopaedia of Anatomy,' and 'On the 

 Minute Structure of Voluntary Muscle/ in 'Phil. Trans./ 1840, 

 II, 1841, I ; J. Hoist, ' De Structura Musculorum in genere 

 et annulatorum Musculis in Specie/ Dorp. 1846; M. Barry, 

 'Neue Unters. iiber die schraubenformige Beschaffenheit der 

 Elementarfasern d. Muskeln, nebst Beobachtungen iiber die 

 musculos. Natur d.Flimmerharchen'(Miill/Arch./1850,p.529). 



1 [It has been pointed out to us by Professor Sharpey, that Leeuwenhoek 

 was not acquainted with the anastomosis of the primary bundles of the cardiac 

 muscles, but has described and figured only that of the secondary bundles, which is 

 indeed obvious upon reference to Leeuwenhoek's Plate (' Experimental et Contem- 

 plationes,' Op. Om. Lugd. Bat., torn, i, p. 409, 1722); the ascription in the text is 

 therefore an error. For other remarks upon the muscular tissue, vide infra, 

 § Muscle. — Eds.] 



2 [Such branched muscular fibres may be found beautifully marked in the upper 

 lip of the Rat, and in the tongue of Man and Animals. See article 'Tongue,' by Dr. 

 Hyde Salter, in Todd's 'Cyclopaedia.' — Eds.] 



