ON THE EXANTHEMATA 59 



The phenomena constituting the early stages of the 

 exanthematous diseases vary greatly in the degree of their 

 intensity, their manner and sequence of manifestation, and 

 the length of time occupied in their development and 

 evolution, the period of incubation, as it is called, occupy- 

 ing the time stretching from the date of infection to that 

 of eruption, and coinciding with the growth, reproduction, 

 and expulsion of a particular microbic organism. The 

 number of diseases now included in the class of exanthe- 

 mata is very large ; that number, however, we think, is 

 likely to increase as we gain a more precise knowledge 

 of the etiology and pathology of many of those diseases 

 familiar to the dermatologist ; moreover, many of the 

 diseases, undoubtedly exanthematous at times, fail to 

 manifest themselves in their usual eruptive character and 

 manner, and thus elude inclusion in their proper category, 

 hence the necessity for maintaining broad views in relation 

 to classification, and the consequent therapeutic and 

 hygienic action indicated therein. 



