ON AILANTHINB. 263 



easily grown, or more easily increased when grown, than the 

 Ailanthus glandulosa. But to enable this plant when grown to 

 yield a proper supply of food for the ailanthus worm, it is necess- 

 ary to cut it down and grow it ozier-like. In this way young 

 shoots spring forth abundantly, and bear large and delicate leaves 

 fitted for the young worm, and greedily devoured by the older ones. 

 They have an additional advantage also that when the insects are 

 placed upon them in the open air they are more easily protected 

 by nets, &c, from the depredations of birds, insects, &c. 



So much for the plant on which the animal feeds. Let us now 

 turn to the insect inself : — I have already stated that the ailanthus 

 silk worm was introduced into Europe in 1856.. Its cultivators 

 have not been idle since that time as we find that M. Guerin 

 Meneville endeavoured to introduce this worm into France. His 

 first experiment did not succeed but the following year he reared 

 a satisfactory crop of cocoons in the open air ; this, however, and 

 all the efforts of the Societe d' Acclimatization of Paris were not 

 sufficient to effect the general introduction of the animal into 

 France. It became necessary for him to show that agriculturalists 

 might derive a profit, and a good one, from the rearing of this 

 insect. 



Energetic, and thoroughly convinced ofthe success of such an ex- 

 periment on a large scale, he induced personal friends to experiment 

 •on a larger scale at Toulon, in Provence, and at Chinon (Indre et 

 Loire), the one being nearly in the south, the other in the centre 

 of France. 



At Chinon, for instance, 4,500 worms were placed upon flourish- 

 ishing thickets of ailanthus, which had been cut down and grown 

 as bushes with that intention. Their development progressed 

 satisfactorily, and they yielded 3515 excellent cocoons, after suf- 

 fering without injury, rains, heavy storms, and the attacks of 

 birds and insects. The result of the experiment was a loss of 

 about a fourth part, while the average loss of mulberry silk-worms 

 is about one-half. 



M. Meneville, after some careful experiments and calculations 

 which w T ere submitted to the imperial government, has thus stated 

 his profit and loss account, on the rearing of ailanthine, or 

 the silk of this worm, produced in districts south of Paris. 



Francs. 



Twelve acres of ailanthus copse, share of expense of planting 



and annual expense of keeping up 2030 



Average of receipts from two crops of ailanthine 9945 



