^O Mr. A. B. Farn on the 



needle or a pin. The newly-disclosed worm thus incontinently 

 dragged into existence had to comfort itself with lettiace-leaves, 

 and these sometimes by no means of a succulent nature ; and he 

 was a lucky worm indeed which survived until mulberry-leaves 

 came in, and then he had but the coarse leaves of the black mul- 

 berry ; the tender, fine-textured, leaves of the ichitc mulberry 

 never entered into his wildest dreams. Yet, despite rough 

 handling and indifferent food, some worms survived to produce 

 a vei-y fair cocoon. If we believe in the survival of the fittest, 

 — and the race is still continuing in schoolboy hands, — I very 

 much doubt whether now anything less than a sledge-hammer 

 could seriously injure it. 



But on the Continent, where silkworms were reared by myriads 

 and every care was taken of them, it somethnes happened that 

 entire broods died before reaching maturity. The eggs carefully 

 retarded in development by being kept in a cool place until the 

 tender leaves of the white mulberry were sufiSciently advanced ; 

 the larvse reared in houses constructed on scientific principles, 

 neither too hot nor too cold, and properly ventilated, surrounded 

 by everything that experience could dictate for the advantage of 

 the worm ; yet meeting with nothing but disaster. In France, 

 so terrible was the mortality of the worms, that the annual 

 crops of cocoons had fallen from 26,000,000 kilogrammes to 

 4,000,000 kilogrammes, causing a loss of at least £4,000,000 

 sterling in one year alone. Events seemed to point to the total 

 extinction of the silkworm. Nurserymen, who were rearing the 

 white mulberry- trees to transplant to the silk-rearing localities, 

 found themselves almost bankrupt. Trade in the South of 

 France suffered generally, for the most important debts incurred 

 during the year were usually satisfied after the silk harvest ; and 

 one can readily imagine all sorts of ramifications of distress 

 when the silk crop proved a failure. 



All rearers of silkworms had at times lost their broods from a 

 cause they could readily understand, but here was a disease as 

 mysterious in its operations as it was fatal. When healthy 

 worms are approaching maturity they eat incessantly, taking in 

 an enormous quantity of food, of which a very large proportion 

 is fluid. The only way the larvae can dispose of this fluid (as 

 they do not urinate) is by an imperceptible evaporation, through 

 their skins, and anything which checks or suppresses this evapo- 

 ration is deadly to the larvae. In warm humid weather, when 

 the atmosphere is saturated by moisture, unless the temperature 

 of the rearing-houses is maintained so that the air therein is 

 kept artificially dry, the worms can no louger dispose of the 

 superfluous moisture within them. The contents of their ali- 

 mentary canal forthwith ferment, and the larvae are seized with 

 diarrhoea, turn rapidly black and putrefy. This disaster, Low- 



