THE SILKWORM-DISEASE. 161 



appearance of the moths alone is waited for. They 

 arrive, and they pair. Then begins the work of the 

 cultivator, who is careful about the production of his 

 eggs. He separates the couples at the end of the day ; 

 laying each female moth by itself on a little linen 

 cloth suspended horizontally. The females lay their 

 eggs. After the laying, he takes each female in turn 

 and secures her by a pin passed through the wings to 

 a folded corner of the little cloth, where are grouped 

 some hundreds of eggs which she has laid. The male 

 moth also might be pinned in another corner of 

 the cloth, but the examination of the male is useless, 

 as it has been found that he does not communicate 

 the pebrine. The female moth, after having been 

 desiccated by free contact with the air, is examined at 

 leisure, it may be even in the autumn or winter. No- 

 thing is easier than to ascertain whether there are any 

 corpuscles in its dead body. The moth is crushed in a 

 mortar and mixed with a little water, and then a drop 

 of the mixture is examined by the microscope. If 

 corpuscles be found, the bit of cloth corresponding to 

 the examined moth is known, and it is burnt with all 

 the eggs it contains. 



This method of procuring pure eggs is, in fact, only 

 the rational development of the first inductions which 

 Pasteur had submitted to the Agricultural Committee 

 of Alais in June 1865. At that time he hardly ven- 

 tured to hope that he should be able to find the means 



