497 



])()siti(»ii upon tliciu by Bn(c/ni.s i))-uiitLini.s which has otherwise 

 been quite ready to oviposit iiium verv diverse seeds. 



The seeds of Delonlx rcjjia. Acacia yrandis. and of PcUo- 

 phovum inerme among others are covered with a very dense and 

 liard covering,- and it is doiibtfid if any llniclihl hu'va conld 

 pierce thcni. Eggs of Bruclms pruudnu.'^ laid on the seeds 

 of the latter species hatched properly but (Mmhl not ])enetrate 

 into the cotyledon, perishing before they had ijierccd the seed 

 coat. They could not, likewise, peni^trate the tough seed coat 

 of Acacia faiiiesiana. 



Within the seed coat of uniny leguniinous seeds is an al- 

 bumen which is very hard and tough when dry and this may 

 serve as a suificieut bari-ier to prevent the further entrance of 

 the lar\-a. The seeds of Cassia glauca resemble the seeds of 

 Leucacna glauca and BrucJins prninimis deposits its eggs upon 

 them freely l)oth in the tield and in captivity. The seed coat 

 is, however, harder and there is a layer of alluimen within 

 that. The bruchus larva is aide to pierce the seed coat but 

 jicrishes on its way through the albumen. 



Seeds, not otherwise defended from bruchus attack, may 

 be unfit for the food of the l)ruchus attacking it and the larva 

 may perish as the result of feeding on the substance of the 

 cotyledons. 



Leguminous seeds vary greatly in their composition but 

 appear to agree in having similar proteids wdiich, as a group, 

 differ from the proteids of other seeds, being said to resemble 

 animal ])roteids more than those of grains or oil seeds. Their 

 ])roteids ar(^ mostly globulins and the globulins of different 

 species of edible legumes are by no means identical. Thus the 

 ]ihaseolin of the common bean is distinctly different from the 

 legumin and vicilin of vetches, broad beans, lentils, and peas 

 and it is not improbal)le that the inability of brnchids to breed 

 in legumes otherwise similar in composition to their host seeds 

 may be due to the diversity of ther proteids. The seeds of 

 many legumes, particularly the greater part of the edible le- 

 gumes, contain more than half their dry weight of starch, 



