174 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 



V. Connective Tissue.— Boll, "The Structure anclDevelop- 

 nient of Tissues." [Of this paper, to Avhich we referred in our 

 last, the following is an abstract, taken from 'Centralblatt,' No. 

 47, 1871.] The investigations recorded in this paper are con- 

 cerned with the connective tissue substances, and especially 

 with their development; the three sections now published deal 

 M'ith (1) Tendon ; (2) Fibrillated connective tissue. 



(1) Tendon. — For the study of this tissue in its embryonal 

 condition Boll made use of embryoes of the common fowl 

 from the eighteenth to the twenty-first day ; as well as 

 rabbits, guinea-pigs, and dogs, from the last third of intra- 

 uterine life, studying especially the centrum tendineum 

 deprived of its serous coverings. When the fibrous bands 

 are examined, either fresh or preserved in M tiller's solution 

 or pyroligneous acid, it can be seen that between the 

 parallel bundles of fibres here and there are inserted darker 

 and granulated stripes composed of flat cells arranged close 

 together, precisely in a straight line. When isolated they 

 are seen to be rectangular and rhomboid elements, with 

 coarsely granular protoplasma and generally distinct nucleus, 

 and are further specially characterised by a bright stripe 

 with dark granules (called by the author the " elastic 

 stripe") Avhich runs sometimes along the edge, sometimes 

 in the middle, but always in the direction of the greatest 

 diameter, and through the whole length of the cell. The 

 connection of the cellular plates and the chain formed by 

 them to the fibrillse. Boll believes to be shown by longi- 

 tudinal and transverse sections to be as follows : — that the 

 cell plates are cemented to the surface of the bundles and 

 embrace them in the form of a half-complete sheath. 



In the study of the completely developed tendon Boll fol- 

 lowed Ranvier in using the minute tendinous threads from 

 the tail of young Rodentia which could be examined without 

 any further preparation. The object was fixed by sealing- 

 wax, and an acid solution of carmine added, which had the 

 effect of bringing out here and there between the homogeneous 

 fibrillje intensely coloured stripes parallel to the long direction 

 of the tendon which were straight, or else more or less curved 

 according to the degree of tension of the tendon. These 

 stripes were made up of segment, separated by hardly per- 

 ceptible boundary lines, each of Avhich segments corresponds 

 to the stripe called by Boll the elastic stripe, of each indivi- 

 dual cell. This stripe was very intensely coloured by the 

 carmine, while the rest of the cell, even the nucleus, took a 

 very faint colour. When the tendon is much contracted 

 (being little stretched, or not at all) the stripe ajipears, not 



