CYTORYCTE8 VARIOLA. 733 



The conclusion that conjugation takes place is based Nuclear 

 on certain analogies with other micro-organisms, rather sta&es. 

 than on observation of the phenomenon. This intra- 

 nuclear mother organism, the product of conjugation, 

 finally grows to a size of 10 to 12 microns and forms 

 within it from eight to twenty "primary sporoblasts." 

 The young sporoblasts are eventually liberated from the 

 mother cell and are at first solid and homogeneous, like 

 the gemmules, but later when they have reached a size of 

 iy s to 2 microns small vacuoles appear in the peripheral 

 ring of substance and in each vacuole a young spore is 

 formed. The formation of these spores terminates the 

 "primary nuclear phase" of the organism. These spores, 

 still within the nucleus of the epithelial cell, become, 

 in their turn, sporoblasts, and the formation of a large 

 number of secondary spores within them constitutes the 

 secondary nuclear phase of a parasite. In the mean- 

 time the nucleus of the epithelial cell has degenerated, 

 and the secondary sporoblast with its contained spores 

 escapes first into the cytoplasm and eventually into the 

 pericellular space. In accordance with this conception 

 the intranuclear process is well calculated to give rise 

 to a massive number of young parasites within the body. 

 Councilman, Magrath and Brinckerhoff state that after 

 the tenth day of the disease the parasites become more 

 and more difficult of recognition by microscopic methods. 

 However, Brinckerhoff found that even the desiccated 

 crusts of pustules and vesicles produce typical lesions 

 on the cornea of the rabbit. These forms have never 

 been recognized positively in the blood of patients, and 

 Magrath and Brinckerhoff were not able to produce le- 

 sions in the rabbit's cornea by inoculation of variolous 

 blood. The general distribution of the lesions in the 

 skin and the occurrence of fetal smallpox gives us abun- 

 dant reason for believing that the blood stream is in- 

 vaded by the parasites. 



It was stated above that bodies of the general nature cytorycetes 

 of those described are found in vaccinia as well as in in Vaccinia, 

 smallpox, and this occurrence is some added reason for 

 believing that Cytoryctes variolce, s. vaccinice, is the 

 cause of these processes. It is a most interesting and 

 important observation by the American authors cited 



