112 INTERSTITIAL INFLAMMATION. 



that the vessels of inflamed parts are surrounded hy sl layer of 

 young round-cells ; and this holds good even of those vessels 

 which extend far into tissues which have as yet undergone but 

 trifling change. On the other hand, we can give a satisfactory 

 explanation of the drawing, which represents " connective tissue 

 undergoing proliferation," by assuming that it exhibits the 

 colourless corpuscles " during migration," in which case they 

 would naturally select the lines of least resistance, and therefore 

 those interfibrillar channels which are normally occupied by 

 the stationary corpuscles of the connective tissue. 



^ 90. The migration of the colourless corpuscles must not, how- 

 ever, be regarded as the 07ili/ source of the inflammatory products. 

 On the contrary the question, Whence can the blood obtain such 

 a multitude of colourless corpuscles ? leads to a series of consi- 

 derations which tend to make us very chary of rejecting any 

 possible sources from which these cells may be derived. On this 

 ground we gladly welcome the beautiful researches of Strieker, 

 which prove, at least with regard to the cornea, that a few hours 

 after it has been irritated with lunar caustic, at a period when 

 the colourless corpuscles can be experimentally shown not to have 

 penetrated as far as the seat of inflammation, the stationary 

 corneal corpuscles exhibit a series of changes which can only be 

 interpreted as steps in a progressive metamorphosis. They 

 retract their processes ; their nuclei undergo multiplication ; 

 their protoplasm increases in bulk ; between the fifteenth and 

 the twenty-second hours they assume the appearance of mobile, 

 multinuclear masses of imposing size, which remind us vividly of 

 the so-called " giant-cells " (see § 67). It is but a step to the 

 assumption that these may give rise to amoeboid cells by a seg- 

 mentation of their protoplasm. 



The same author has directly observed the fissiparous multi- 

 plication of the emigrant-cells at the seat of inflammation. 

 Concentrating his attention on the cells which appeared to be at 

 rest just outside the vessels, he noticed on their surface certain 

 lines of shadow, which came and went and shifted their position 

 for a time, until at length a shadow deeper than the rest became 

 stationary in the middle of the cell. At this point the little body 

 became contracted ; the contraction itself was more than once 

 eff"aced ; when it finally passed into a complete division, the two 

 halves crept asunder in opposite directions. The denser the 



