24 THE CULTURE OF THE MULBERRY SILKWORM. 



THE FOURTH AGE. 



When the worms are over their third molt they cease to be gray, 

 and take the characteristic color of their race. If they are too long 

 in molting it is because the temperature is too low; that is, below 68° 

 P. Increasing the heat a few degrees will excite the worms and enable 

 them to complete their change. After this the teraperatuie adopted 

 for the rearing must graduall}'^ be resumed. 



When all the worms have molted the third time a change of beds 

 must be made as in preceding ages. Do not be in haste to change. 

 Wait a few hours to permit the woi-ms to recover their strength a 

 little. The recommendation to feed lightly at first applies especially 

 to the beginning of the fourth age. 



If the outside temperature is normal, fires need not be kept up, and 

 the doors and windows may be left open, guarded by light curtains. 

 In this age the worms eat enormouslj^ and more help will be required 

 to gather and distri])ute leaf. Small branches of leaf may now be given 

 in place of whole leaves, and the niunber of meals may be reduced to 

 four, if the temperature is 68° to 70° F. , at which temperature the 

 age will last nine days. If it is desired to reduce this age to seven 

 or eight days, raise the heat to 72° F., and give five or six meals daily. 

 Should change of weather retard the growth of the mulberry trees, and 

 temporarily cut off the supply of leaf, adapt the rearing to such a con- 

 tingency by lowering the temperature slowly to GG'-' or 68° F., and giv- 

 ing only three or even two meals daily. Then, when leaf is obtained, 

 gradually raise the temperature to the degree adopted for the rearing. 



During the fourth age four changes of beds are made, including the 

 one which follows the third molt. A single division of the worms is 

 sufficient, which will be the last, and particular care must be taken to 

 divide the worms into two equal parts. For this, spread the nets or 

 perforated paper over the worms when half are molting and proceed 

 as T)efore. 



THE FIFTH AGE. 



Do not be in haste to change beds as soon as the worms have molted. 

 This precaution is necessary to allow the new organs to acquire con- 

 sistency, and to prevent worms from being lost in the litter. Conse- 

 quently, wait several hours, and change beds after the second meal, 

 the first being onl}^ a slight sprinkling of leaves. Worms are not 

 strong enough immediate!}^ after a change to digest a heavy meal. 



The space during this age should not be limited. See that between 

 two worms another could be easily placed. Experience has proved 

 that the harvest of cocoons is often in proportion to the space accorded 

 to the worms during this age. 



Feed from four to six times daily, according to the temperature, 

 and spread the branches or leaves out regularly, not to form a mass. 

 For a simultaneous mounting into the brush all the worms should eat 

 an equal quantity" of food. 



