CULTTTRE OF SliKWOUMS. 
13 
Silk Committor to apply the Pasteur Kyst€m to the multivoltine 
wtirtiit?, I will stiit-e here whiit my exjierience hm V>een, the way 
I h;tve (;jLrrieil out the system and the plan whieh I pr(.)p«se for 
a<li>i*tiou on a large scale. 
The moths on coming; ont of the cocoons are allowed to 
jtair. and in the t?veniug are separattxl, the iiialet* bcinj^^ thi'tiwn 
away and the females ln^iiig placv^ each in a siuall cone of pajier. 
one corner of which is then tmrnyd in so as to i^los*) its mouth. 
These paper cones are strunjj^ iiji and the e^gs laid in them. On 
tho tiJth or fiixth day after layhi^^. the moths are each taken and 
crushed in litlie china cups with a i^^lnsw i)estle. A drop of the 
fluid is transferred to a glass slide and a ettver glass put over it. 
These slides are then examined with a qnarter-iiich ol)ject ghiss 
iind lugh |K>wer eye-piui-e, giving a magnifying power of tMiO dia- 
meters. The eggs of all diseased moths are then destroyed, and 
the healthy ones only n^serviid fttr i breeding. On two occasions, 
stitrting with highly pebriiiised worms, I eradicated the disease 
in from three to four geueriitions by the above course of pro- 
cedure. 
PROPOSED SYSTEM TOE PASTEtTBIZIKO 
MULTIVOLTIlSrE SILKWOUMS. 
The selectioE, hj the microscope, of a large numlier of eggs, 
ill the way above descriljed, is a commercial imijossiliihty, as there 
;ire only six or seven working days Iwtween the laying of the eggs 
and the haiehing oi' multivoltine wonus. instejtd of aiiout as 
many months in the case of the annual ijilkworms cultivated in 
Europe. 
My plan for overcoming this difficulty is maintain a breetl 
of say 3,000 wonns, wluch for eom-enience may he ealled '' firsts." 
This breed is to Ijt^ kept distinct and t** Ik* mierosco]tit ji!ly selec- 
tetl every lin)(Kl. Otn- microscopist could esjimine ail the femide 
moths uf each brnod of this nunil>er of worms, In^tween the lay- 
ing and liatching td" the egga. A certain luimtwjr of the eggs from 
thi' l>eat eoeoous wonld ix^ put aside for the next generation of 
*' firsts," and the reuiaining eggs would be reared in se|iarate 
houses, in which strict sanitary j*recautions would Ix? maintained. 
This brood, which would not lie microscopieally selected, 
may Ik.' called " seconds.'* On attaining maturity these " see- 
ouds" would lay, aofl it is their eggs which would be given to 
tho cultirators. 
They would therefore be always only onee removed from 
the "first" or microscopically selected eggs, If 1,200 female 
moths out of the 3,000 above-mentioned were passed at a 
