50 GENERAL ANxlTOMY OF THE TISSUES. 



veloped into a spiral fibre ; and I published a concise notice 

 of the fact in the year 1849 (' Zeitschrift fur wiss. Zool./ Bd. i, 

 p. 215, Anmerkung), a view which has since been confirmed by 

 H. Meyer (Ibid., Bd. i), and more recently by Leydig (Ibid., 

 Bd. iii, Heft 4). 



Literature of the Elementary parts. — In addition to Schwann's 

 work quoted above, may be named: Kolliker, 'die Lehre von der 

 thierischen Zelle/ in Schleiden u. Nageli's ' Zeitschrift fur 

 wiss. Botanik./ Heft ii, 1845 ; Remak, ' Ueber extracellulare 

 Entstehung thierischen Zellen und die Yermehrung derselben 

 durch Theilung u. liber Entstehung des Bindegewebes u. d. 

 Knorpel/ in Muller's 'Archiv/ 1852, i. (No longer available. 

 Bemak assumes quite confidently, what I only indicated, that 

 animal cells have a primordial utricle, without giving any 

 demonstration of the fact; he describes the multiplication of 

 cells by division to be widely extended through embryonic 

 tissues ; finds (what others will not easily succeed in doing) two 

 membranes in the later cleavage-masses, and wrongly, denies 

 altogether the occurrence of free cell-development) ; also the 

 treatise of Donders, cited below under the head of elastic 

 tissue ; and the embryological monographs of Reichert, Bischoff, 

 Yogt, Remak, and myself. Inasmuch also, as the doctrine of 

 the vegetable cell is important for zoologists, I call attention 

 to Schleiden's first treatise (' Abhandlung liber die Bildung d. 

 Pflanzenzelle/ Mull. 'Arch./ 1837); to his 'Elements of Botany;' 

 to Nageli's Essay ' Ueber die Pflanzenzelle/ in the ' Zeitschrift 

 fiir wissenschaftlich. Botanik/ Heft ii; and to MohPs Mono- 

 graph upon this subject, in Wagner's ' Handworterbuch' 

 ('Mohl on the Yegetable Cell/ translated by A. Henfrey, Lon- 

 don, 1852). [To these should be added the more recent works 

 of Dr. H. Schacht, ' Die Pflanzenzelle, &c./ Berlin, 1852 ; and 

 of Alex. Braun, ' Ueber verjiingung/ Leipzig, 1851. — Eds.] 



Ill— OF THE TISSUES, ORGANS, AND SYSTEMS. 



§ 20. 



The elementary parts of both the simpler and the higher 

 kinds, are not dispersed irregularly in the body, but are united 

 according to determinate laws, into the so-called tissues and 



