64 GRAPE CULTURE AND 



the form corresponding in the biological series to the winged 

 form, though never developing wings. 



Hibernating Forms. The hibernating larva is the final 

 form of the year's development, upon which the future multi- 

 plication of the insect is dependent. This, and the winter 

 eggs, serves to carry the insect through the winter. It seems, 

 according to our observations^ that this special precaution is 

 not necessary, and is therefore not apparent in the California 

 climate. Our winters are so mild that merely a cessation of 

 work is noticeable, and not an extermination of the common 

 forms. The young larva of the common egg-laying insect 

 acts as hibernants without any apparent special prepara- 

 tion, and it seems to brave our winter without any trouble. 

 The mother insect can also be found, although with difficulty. 

 The larvae themselves, in some cases, seem to have assumed 

 some of the qualities of the true hibernants, for they are strong, 

 and usually darker in color, often almost black. 



In connection with the habits of the phylloxera during hi- 

 bernation, an instructive sample of infested root was preserved 

 this year, in an open vessel, filled with moist earth. The roo 

 was protected from the earth and placed so that it could be 

 watched through the sides of the vessel without being disturbed. 

 Scarcely any change has been noticed since October fifteenth, 

 when^the specimen was prepared. Although the conditions 

 have been quite similar to that of ordinary vine growth, ex- 

 cept somewhat drier, there has Deen no movement to other 

 parts of the root corresponding to the supposed movement of 

 the phylloxera to lower roots when winter comes on. The in- 

 sects have become somewhat darker, well developed young 

 larvae, with no appearance of the adult larvae form. Up to 

 February, 1886, there has been no appearance of reviving or 

 moving about, still the extremities of the insect are extended 

 and can be plainly seen as in their natural condition in sum- 

 mer. It is to be hoped that interesting facts may be gathered 



