376 Mr. Theodore Wood on 



two weevils, bore in all six pods, of which five came to 

 perfection ; two of these plants, however, were barren. 

 The remaining twelve, the seed of which had sustained 

 but one perforation, produced twenty-three pods, of 

 which not more than ten arrived at their full size. Only 

 one of these latter plants, however, was altogether un- 

 fruitful. The twenty plants thus bore among them 

 thirty-two pods (six to a plant being with this variety 

 considered the normal number), and even of these 

 barely one-half attained to their full development. That 

 the seed itself was not in any way deficient, apart from 

 the injury caused by the beetles, was sufficiently proved 

 by the fact that the plants raised from the remainder, 

 which were free from the weevil, yielded an average 

 croj). I therefore concluded that the presence of the 

 Bruchus in the seed, although only in exceptional cases 

 affecting the germinating powers, was yet highly preju- 

 dicial to the reproductive capabilities of the adult plant. 

 I also found that, with one exception, the plants raised 

 from weevilled seed were altogether passed over by Aphis 

 rimiicis, which attacked almost every other bean-plant 

 in the garden, and destroyed at least one-third of the 

 entire crop before it was fit for gathering. From this I 

 inferred that the sap of the weakened plants was of too 

 deteriorated a character to be suitable for Aphis nourish- 

 ment. I have since found reason to modify the former 

 of these conclusions in some cases, and in some degree. 



Before proceeding to discuss results, however, I will 

 specify the conditions under which the second series of 

 experiments were carried on. I procured in all five 

 varieties of infested beans, two of which, the "Leviathan," 

 already mentioned, and the " Seville Longpod," were 

 kindly supplied by Messrs. Carter, who inform me that 

 they have devoted much attention to the possibility of 

 eliminating the damaged from the sound seed. The 

 remaining three varieties consisted of the well-known 

 *' Early Mazagan," and of two more belonging to the 

 longpod section. 



From the packets supplied to me I selected the 

 damaged beans, and sorted them out in accordance with 

 the number of perforations sustained by each. Towards 

 the end of March I planted them in well-dug and 

 thoroughly-manured ground, under the most favourable 

 conditions for their subsequent development. Of the 



