LEPIDOPTEEA. 235 



When they have awoke out of this last sleep the attendant 

 should continually be on his guard, as it is then that diseases 

 break out. The worms suffering from these different diseases 

 have received different names. There are besides the luisettes, the 

 arpians, that is to say, worms that have exhausted all their energy- 

 in the work of the last moult, and have not even strength to eat ;. 

 the yellow or fat worms, which are swollen, of a yellowish 

 colour, and which very easily die. The flats or mous, the soft or 

 indolent ones which, after having eaten a great deal and become- 

 very fat, die miserably and enter into a state of putrefaction. 

 And lastly, it is at this age that the muscadine, which hardly 

 shows itself at any other age of the insect, appears with great 

 intensity. 



The muscadine is a terrible scourge to the rearers of silkworms^ 

 The losses which result from this disease in France are estimated 

 at at least one-sixth of the profits. No particular symptom 

 allows of our recognising the existence of this disease in worms 

 which, however, contain its germ. Only, the worm, which has 

 eaten up to that time as usual, appears almost in a moment to change 

 to a duller white ; its movements become slower, it becomes soft, 

 and is not long before it dies. Seven or eight days after its death 

 it becomes reddish and completely rigid. Twenty-four hours 

 afterwards a white efflorescence shows itself round the head and 

 rings, and soon after the whole body becomes floury. This flour 

 is a fungus called Botrytis bassiana, of which the mycelium 

 develops itself in the fatty tissue of the caterpillar, attacks the 

 intestines, and fructifies on the exterior. This fungus has been 

 considered as the immediate cause of the muscadine, and has been 

 also regarded as the last symptom or end of the disease. The 

 communication of the disease by contagion has alternately been 

 admitted and denied. As its true cause, and any efficacious 

 means of opposing it, are still unknown, -the breeders of silk- 

 worms must be content to apply, so as to prevent or struggle 

 against this dreadful scourge, the precepts of hygiene : good 

 ventilation, excessive cleanliness, frequent delitements, and good 

 food properly prepared. 



After the muscadine, we must mention another epidemic disease 

 still more terrible : the gattine. This disease shows itself from the 



