834 



SCIENCE 



[N. S. Vol. XLI. No. 1066 



ceous and Tertiary, and checking the accuracy 

 of conclusions derived from other lines of 

 evidence. I. W. Bailey, 



E. W. SiNNOTT 



BussET Institution, 



BREVARD UNIVEESITT 



THE BROWN GRAPE APHID 



This aphid is commonly known as Macro- 

 siphum viticola Thomas. Unable to find any 

 record of its complete life cycle the writers 

 have made some observations on the form at 

 Vienna, Va. These seem worthy of note at 

 the present time, in view of the economic im- 

 portance of the species. 



The eg'gs are polished black and are laid 

 during November or late October. They are 

 placed in the axils of the leaves of Viburnum 

 prunifolium Linn. In the spring they hatch 

 before the leaves open and the young feed on 

 the bursting flower buds. The stem mother 

 appears unlike a Macrosiphunij having short 

 cornicles. Late in April, or in early May, the 

 second generation matures and this nearly all 

 becomes alate. 



Such alate forms are unable to subsist on the 

 Viiurnum, but migrate to the grape and pro- 

 duce the third generation on that plant. Here 

 the species lives throughout the summer, pro- 

 ducing apterous and alate forms. We have 

 also some intermediates similar to those re- 

 cently described by us in Aphis pomi DeGeer. 

 These intermediates were taken in May and 

 June. 



The fall migrants are unlike the spring mi- 

 grants in sensory characters, the sensoria on 

 the antennae averaging about as follows: Seg- 

 ment IIL, 30; IV., 25; V., 15. These fall 

 migrants may be found depositing their young 

 upon the Viburnum leaves during the middle 

 of October. 



The ovipara is apterous and, after being 

 fertilized by the alate male, deserts the leaves 

 and migrates to the twigs in order to deposit 

 her winter eggs. 



A. G. Baker, 

 W. F. Turner 



Laboeatoey Deciduous Feuit Insect 

 Investigations, Bukeau of Entomology, 

 Vienna, Va. 



THE relation of MITOCHONDRLi TO GRANULES OF 

 THE VITAL AZO DYES^ 



The more ardent hopes which relate to the 

 subject of vital staining are perhaps connected 

 with the successful staining of living, pre- 

 formed components of the cell. Instances of 

 such a phenomenon are often enough alleged 

 without sufficient substantiation. Goldmann,^ 

 whose papers did so much to attract general 

 interest to this subject, believed that the dyes, 

 isamine blue and trypan blue, must be looked 

 upon as combining with some preformed, but 

 hitherto unidentified, elements of the living 

 cell, and this is substantially the attitude of 

 Kiyono,^ who has added the latest considerable 

 contribution to this subject. Tschaschin* of 

 Maximow's laboratory has given this hypoth- 

 esis its most concrete formulation by claiming 

 that we are dealing with an elective, truly vital 

 staining of the mitochondria of connective 

 tissue cells. On the other hand, Evans and 

 Schulemann^ came to the conclusion that the 

 process of staining with these dyes is more 

 intelligible as an ultra-microscopic phago- 

 cytosis, and interpreted the dye granules as 

 storage phenomena, in no way related to the 

 living elements of the cell. In view of this 

 discrepancy in the points of view of different 

 workers, a cytological study of some of the cells 

 which react to azo dyes has been suggested by 

 Dr. Evans and carried out under his direction. 



The study has been limited to cells of sub- 

 cutaneous tissue in adult mice. As has been 



1 From the anatomical laboratory of the Johns 

 Hopkins Medical School, Baltimore. 



2 Goldmann, E. E., ' ' Die iiussere und innere 

 Sekretion des gesnndeu imd kranken Organismus 

 im Liohte der 'vitalen Farbung, ' " Tubingen, 

 1909. "Neue Vntersuchungen usw.," Tubingen, 

 1912. 



3 Kiyono, ' ' Die vitale Karminspeicherung, ' ' 

 Fischer, 1914. 



4 Tschaschin, S., Folia Ewmatologica, Bd. XIV., 

 S. 295, 1912; Bd. XVI., S. 247, 1913, Bd. XVIL, 

 S. 317, 1913. 



5 Evans and Sohulemann, Jahresb. d. Sch. Ges. 

 f. Vat. Kul., 1913 ; Science, Vol. XXXIV., p. 443, 

 1914; Vewt. med. Wochenschr., No. XIII., 1914. 



