The Pebrine Corpuscles in the SilJcworm. 179 



of equal apparent health, contained the seeds of the devastation 

 which had blasted their hopes of profit for the preceding year. 

 Such, however, has been too frequently the case ; and the success 

 of Pasteur in totally eliminating the disease from those nurseries in 

 which his method was pursued, was due to his recognition of this 

 fact. It is not a little remarkable in this connection, to observe 

 that, 



8. In Pebrine, as in si/phiJis, when one parent only is affected 

 with the disease, healthy offspring may he produced. This general 

 fact was demonstrated by a great number of experiments upon the 

 coupling of moths, in which there was undoubted evidence of cor- 

 puscular disease either of the male or the female. It appeared 

 also from these experiments, that ova entirely sound were gene- 

 rated occasionally by males who exhibited very extensive traces of 

 the malady, when assorted with females who, while they were indu- 

 bitably infected, yet exhibited very few of the i)athognomonic lesions 

 of pebrine. The experimenter explained these circumstances by 

 the conditions incidental to the chrysalis. If the latter became 

 infected with pebrine so as to exhibit corpuscles very soon after the 

 formation of the cocoon, the moth and its ova were almost certain 

 to be similarly diseased. But if this development did not occur 

 until near the time for the escape of the imago, then the ova of the 

 moth might be entirely sound. In the case of the syphilitic ovum, 

 similar results are said to be declared, according as infection occurs 

 early or late in utero-gestation. 



Other analogies between these diseases obviously exist which 

 might be in turn the subject of comment. Such, for example, are, 

 the involvement of the nervous system and centres in each — the 

 infecundity of infected females who are liable to sterility and the 

 production of blighted germs ; the non-inoculability of the infec- 

 tious matter obtained during the later stages of each disease, and 

 the liability of each to complication by the advent of other 

 maladies. 



It should be stated that Pasteur himself is disposed to regard 

 pebrine as analogous to pulmonary phthisis. But he is careful 

 to announce that in establishing a resemblance between the facts 

 which he has observed and those relative to diseases of the 

 human race, he does not speak as an expert.* The hereditary 

 influence of phthisis seems to have attracted his attention to this 

 subject. 



But there are many objections to this view founded upon the 

 clinical history of tuberculosis. This latter disease is neither 



* " Je desii-e toutefois que Ton sache bien que je parle en profane, lorsque 

 j'e'tablis des as3imilatii>ns entre les faits que j'ai observe's et les maladies 

 humaines." 



VOL. XII. O 



