440 LECTURE XVIII. 



from these investigations of mine, namely, that a tissue 

 undergoing hypertrophy may supply a completely ab- 

 normal, diseased product, appeared to me all the more 

 significant, because I had simultaneously detected an 

 altogether similar series of developmental changes 

 whilst examining an entirely different body, namely, the 

 so-called typhous matter (Typhus-masse). At that time 

 the view of the Vienna school had been universally 

 adopted, that, in the different typhous processes, an exu- 

 dation of an albuminous nature and soft, medullary charac- 

 ter filled the parts, and that thereby swellings of a 

 medullary appearance were produced. But whether 

 the typhous matter be examined in the lymphatic glands 

 of the mesentery, or round about the follicles of Peyer's 

 patches, no exudation capable of organization is at any 

 time met with, but always a directly continuous deve- 

 lopment from the pre-existing cellular elements of the 

 glands, the follicles and the connective tissue, to the ty- 

 phous matter. 



These observations were of course as yet insufficient 

 to justify me in setting about effecting a general change 

 in the existing doctrine, because we see organic elements 

 arise at numberless points, where at that time at least 

 cellular elements were altogether unknown to exist as 

 normal constituents, and there was therefore scarcely 

 any other explanation possible than that new germs 

 were formed by a kind of generatio aequivoca [sponta- 

 neous generation] out of the mass of blastema. The 

 only places besides the glands, where such a develop- 

 ment arising out of previously existing elements might 

 have been inferred with some degree cf probability to 

 take place, were the surfaces of the body with their 

 epithelial elements. Then it was, that my investigations 

 into the nature of the connective tissues, with which I 

 have already so much plagued you, proved entirely de- 



