257 



These changes in form generally proceed gradually. In 

 the course of from two to four hours single cells have already 

 undergone considerable alteration ; they appear to be swollen 

 aaid clouded by granules ; the number and length of their 

 processes thereby become less on the whole, since individual 

 cells are now possessed of only one or two more short thick 

 processes. 



Our examination could not be extended until the complete 

 retraction of the processes, for as soon as granular stasis came 

 on the apex rapidly became clouded and the creature died. 



We have obtained preparations of tadpoles' tails which, in 

 about two hours after they have been irritated in the manner 

 above described, were cut off and coloured in the usual way 

 by chloride of gold. In the successful preparations we missed 

 at once in the neighbourhood of the vessels the characteristic 

 forms of branched cells, as observed in the gold preparations 

 of normal tails. We found at numerous spots, especially near 

 vessels in the walls of which colourless blood-cells were in- 

 cluded, more irregular, large, and granular cells set with 

 small bosses, and furnished with two or three short and rela- 

 tively thick processes. Besides these could be observed 

 transition forms from the cells just described to the sym- 

 metrical non-granulated cells furnished with numerous 

 branched processes. 



10. On Inflammation and Suppuration. By S. Stricker. 



( Concluding Essay . ) 



W^e distinguish, as is well known, two ingredients of pus, 

 namely, formed elements and a fluid in which these are 

 suspended. Concerning the source of the fluid there is no 

 dispute. It is held as a general opinion that this proceeds 

 directly or indirectly from the blood. We discuss here the 

 genesis of the formed elements. 



The resemblance of these formed elements to the colourless 

 corpuscles of the blood long ago favoured the view that the 

 pus -corpuscles had their origin in the blood. Advancing 

 knowledge, however, has much diminished the value of this 

 opinion. 



We have learnt that the corpuscles of pus, like those of the 

 blood, are contractile ; we recognise in both some which are 

 more and some which are less granular ; we allow, finally, 

 that their absolute size, and also the relative proportion of 

 the cell itself and of the nucleus, may present manifold 

 variations. But so far we have enumerated all the hitherto 

 known characters of young cells. It may then be assumed 

 that pus-corpuscles are similar to blood-corpuscles, for the 



VOL. X. — NEW SER. S 



