172 STUDY OF INFLAMED TISSUES. 



to be larger than natural, while their processes become thicker 

 and less branched. Immediately under the epithelium, as well 

 as under the endothelium of the posterior surface, the pro- 

 cesses often exhibit node-like enlargements. Occasionally 

 corpuscles occur which possess processes only on one side, 

 while on the other they merely exhibit slight prominences. If 

 a cornea of this kind is immersed in solution of chloride of 

 gold for twenty minutes and treated as usual, the corpuscles 

 are seen to be much more stained in certain parts than in 

 normal corneas, although the latter may have been immersed 

 twice as long. If a comparison is made between different 

 parts, it is easy to satisfy one's self, that the strongly colored 

 corpuscles are larger and look as if they were swollen, and 

 that their processes are fewer in number and thicker. The 

 nuclei of these corpuscles exhibit the most various phases; 

 constrictions and bulgings are seen in some, complete division 

 in others. 



This is by no means the final stage of the alteration of the 

 corpuscles. It may be demonstrated at a later period that in 

 some parts no branched corpuscles can be distinguished, their 

 place being taken by a trellis-work of spindle-shaped cells, 

 presenting the aspect of parallel streaks of granular protoplasm, 

 running in two directions at right angles to each other. In 

 each streak there are thickenings at intervals. Each thicken- 

 ing may contain either a few deeply stained small nuclei, re- 

 sembling those of the neighboring migratory cells, or nuclei 

 with constrictions which resemble those which are character- 

 istic of the cornea corpuscles. Between these larger swellings 

 containing nuclei, the streaks are beset with small nodosities 

 of various sizes. If these streaky parts are compared with 

 others, it is seen that there are all transitions between the 

 streaks and regularly branched oblong cornea corpuscles, while 

 in other directions their relation can be traced with chains of 

 young cells, which run in the same direction as the streaks. 



The entrance of migratory cells, and even a beginning of 

 the changes above described in the cornea corpuscles, may be 

 imitated in an excised health}- cornea, as follows : Inflammation 

 is produced in one eye b}^ cauterization, and then, twent3 T -four 

 hours after, a portion of the cornea of the other eye is excised, 

 spread out carefully, and lodged between the membrana nic- 

 titans and the cornea of the injured eye. The merabrana nic- 

 titans is then drawn up and secured by two or three ligatures 

 to the skin. After twenty-four hours more, the sac is opened 

 and the cornea taken out. It may be examined in the fresh 

 state, and after preparation with gold. 



Corneas prepared in other ways (e. <?., by gentle friction with 

 solid caustic, as directed in Chapter II., or by holding the 

 head over hot water, and brushing the surface with a camel- 



