44 THE SAX JOSE OK CHINESE SCALE. 
hibernates in the nearly mature condition, as does the San Jose scale. 
and deposits eggs in the spring or early summer. The viviparous 
habit, or the giving birth to the living young, possest by the San Jose 
scale, finds a parallel in many other insects and frequently in aphides. 
In the case of the San Jose scale the eggs are fairly well formed, 
a few at a time, within the body of the mother. What takes the place 
of the eggshell consists of a very delicate and thin membrane -the 
amnion — which incloses the developing larva and which at the moment 
of birth is cast off. and remains attached to or partly within the ovi- 
duct. The amnion is probably pushed out by the next larva in turn. 
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Fn;. 3.— Young larva and developing San Jose scale (Aspidiotus perniciosus): a, ventral view of 
larva, showing sucking beak with seta- separated, with enlarged tarsal elaw at right: b, dorsal view 
of same, still more contracted, with the first waxy filaments appearing; c, dorsal and lateral views 
of same, somewhat contracted, illustrating further development of wax secretion: <1, later stage of 
same, dorsal and lateral views, showing matting of wax secretions and first form of young scale. 
All greatly enlarged (from Howard and Marlatt). 
The difference between this mode of birth and the ordinary method 
thru the medium of true eggs is simply that what corresponds with 
the egg is retained by the female until the larva is developed, instead 
of development of the larva progressing after the egg leaves the 
parent. 
The emergence of the young from the female over a period of six 
weeks leads to a very confusing intermingling of generations and 
renders it difficult to make observations on the life history except by 
isolating and watching: individuals. 1>\ means of such isolation of 
individuals, however, we have been able to most carefully trace the 
