230 MANUAL OF HISTOLOGY. 



surplus to the radicals of the absorbents contained in the tissue ( 82). 

 Unfortunately, the amount of this fluid is too small to allow of oui 

 obtaining it for chemical analysis, so that its composition still remains 

 unknown. Conclusions as to the constitution of the normal fluid drawn 

 from analysis of those abnormal collections met with in formless connec- 

 tive-tissue in oedema, appear to us inadmissible. 



In the serous t=acs and cavities likewise we meet with a very similar 

 fluid, in varying but usually small quantity, which might be named a 

 watery exudation from the intercellular fluid of the blood, containing, on 

 analysis, albumen, extractive matters, salts, and at times also fibrin (1). 

 Up to the present, the only fluid contents of any of the true serous 

 sacs that have been examined, under completely normal conditions, are 

 those of the pericardium in the case of executed criminals (Gorup- 

 Besanez and Lehmann). The results varied. The first of these investi- 

 gators obtained in two cases a fluid of weak alkaline reaction and yellowish 

 colour. 



1000 parts of pericardial fluid consist of 



1. 2. 



Water, . .. .' . . 962'83 955-13 



Solid constituents, . -.,< . 37'17 44-87 



Albumen, . ;.. i 21 '62 24'68 



Fibrin, . ....,;.,';. 0-81 



Extractive matters, . . . 8'21 12-69 



Salts, . \i . ,.. ; .,, 7-34 6-69 



Lehmann, on the other hand, only obtained 8'79 of albumen, 0'93 of 

 other organic matters, and 0'89 of mineral constituents, per thousand. 

 For synovia (comp. p. 155). The intercellular matter of connective- 

 tissue, together with the fasciculi of the latter, consists of a glu tin-yield- 

 ing material. The composition of the cells is, on the other hand, still 

 enveloped in obscurity, while in the elastic elements we may recognise 

 elastin. The intermediate substance of the cornea alone is an exception, 

 in that it yields chondrin. This short notice includes all that was for- 

 merly, and is to a great extent at present known of the composition of 

 connective-tissue. 



In the embryonic state this tissue possesses, according to Schwann's 

 investigations, repeated subsequently by Schlossberger, a ground mass, 

 from which no glutin can be obtained on boiling, and which appears to 

 belong rather to the protein group. This corresponds also with investiga- 

 tions made on the constitution of pathologically formed immature con- 

 nective-tissue, so that we see a parallel between recently formed con- 

 nective-tissue and undeveloped cartilage (11 2). But in that the fully 

 developed tissue, after it has been chemically cleansed, may be converted 

 to a greater or less extent into glutin by boiling, there must take place 

 between the embryonic period and that of maturity some transformation 

 of the albuminoid intermediate substance into a collagenic one. Of the 

 intermediate steps we know nothing, and as to the manner also in which 

 this change takes place we have at present but hypotheses to offer; for 

 we have not as yet been able, as is well known, to effect an artificial trans- 

 formation of the protein substances into glutin or glutinous matters. The 

 chemical constitution likewise of those undeveloped and not yet fibril- 

 lated portions of connective-tissue already mentioned has, with the excep- 



