XJNIVEESIT'X 



\YINE-MAKING IN CJFr\; 63 



Professor Riley has omitted to mention in the table this 

 supposed underground male and female spoken of by M. Bal- 

 biani, which does not pass through the winged state. Accord- 

 ing to this belief, a form similar to that produced by the 

 winged insects may be developed on the roots and pass along 

 the main trunk to the upper part of the vines and deposit eggs 

 in positions similar to those selected by the winged form. 

 This peculiar phase of development would assist in explaining 

 some of the peculiarities regarding the continued prolificacy 

 of the species in California wherr the true male and female 

 appear so rarely, if at all. They may mingle with the com- 

 mon form which is so often found in considerable numbers 

 two or more inches from the ground. 



There is generally a marked distinction between the ap- 

 pearance of the young larvae which are to develop either into 

 the winged form, or are to become mother insects upon the 

 roots. The latter being decidedly dull in habit, and pear- 

 shaped, are quite easily distinguishable; the former are not so 

 easily recognized until the wing-pads begin to appear but by 

 this time they are already so far developed that they become 

 less active, and in bodily form answer more nearly to the de- 

 scription of the wingless type. But then there has been no- 

 ticed on some- of our specimens among these larvae, another 

 form, which in activity and outward appearance closely re- 

 sembles the undeveloped winged insect. It is of a very bright 

 color, apparently smooth, and seems to separate from the re- 

 mainder of the generation as soon as it is capable of moving. 

 It is in fact never found in clusters, and mostly upon portions 

 of the roots which do not show signs of having been attacked. 

 These insects seem to be the explorers for the more sturdy 

 productive ones which follow them. Their peculiarities place 

 them undoubtedly upon the side of the winged form, and as 

 there is presumed to exist a similar line of development, save 

 the formation of wings, we may justly conjecture that this is 



