THE CONNECTIVE SUBSTANCE GROUP. 87 



attracted the study of various histologists for a number of 

 years, since Leidy, in 1849, first directed attention to it, is the 

 mode in which cartilage-corpuscles divide. Various theories 

 have been afloat, each with its special supporters. 



Dr. W. S. Bigelow, of this country, in 1878 reviewed the 

 subject carefully, pursuing his investigations on the* hyaline 

 cartilage of the triton, tree-toad, frog, various fishes, the guinea- 

 pig, total pig, and the human embryo in health and disease. 

 His inquiries were especially concerned with reference to the 

 statement of Buetschli, that in the divisions of the corpuscles, 

 the splitting of the nucleus and cell-body are simultaneous. 

 As the result of Dr. Bigelow' s work, he concludes that the old 

 theory is still tenable, viz., that at first there is a division of 

 the nucleus, and that subsequently a septum is found in the 

 cell-body. After division takes place the matrix of the carti- 

 lage penetrates between the corpuscles, and thus two cavities 

 are formed. This view has received confirmation from very 

 extended and elaborate researches by Schleicher, to which 

 Flemming has also expressed a provisional assent. 



Structure of the cartilage-corpuscle. According to Schlei- 

 cher the nuclei are provided with peculiar filaments and gran- 

 ules which u-ndergo amoeboid movements when they are in the 

 act of dividing. In the cell-body of young cartilage-corpuscles 

 he has seen no network, such as has been described by some 

 later writers (Heitzmann, Klein, etc.), though in the adult tissue 

 peculiar linear markings are evident. He thinks that the nu- 

 cleus is not permeated by a network, but is homogeneous. 

 Eeticulated appearances are apt, he thinks, to be the result of 

 using reagents that alter the natural quality of the tissues. 

 According to Flemming, the nucleus of the cartilage-corpus- 

 cles contains a network which gives the appearances described 

 as " coarsely granular." 



In the drawings of this author the cell-bodies nowhere exhibit a network, 

 but, on the contrary, linear markings, which have often a concentric direction. 

 In many, the internal structure is represented as homogeneous. The conflict of 

 opinion now apparent in this matter, and the marked differences in the micro- 

 scopic drawings of the same object, make it apparent that these topics are still 

 to be regarded as subjudice. 



Structure of the intercellular substance. According to Spina there is an intra- 

 cellular substance in cartilage which is directly continuous with the intercel- 

 lular substance, which itself exhibits an extremely delicate network. This 



