856 THE AMERICAN NATURALIST. [VoL. XXXIII. 
of it in massing the cells much more marked, of course, when 
wings are developed internally. But even here the spindle- 
form cell is recognizable (Fig. 86, 4), and all the cells appear 
still to extend from surface to surface of the hypodermis. 
The first great expansion of the wing occurs just before 
pupation, with insects having complete metamorphosis, but not 
until the final transformation, with those in which the meta- 
morphosis is incomplete. This expansion results in the broad- 
ening of the bases of the hypodermal cells, in the settling down 
of their nuclei close upon the chitine layer, and in the drawing 
out of their inner ends into a long, slender prolongation, which 
Fic. 89. — A, cross-section of the wing of a young acridid nymph: c, cuticle ; 472, 5m, baseme’ 
membrane ; ź, trachea; ¢/, tracheole ; /, leucocyte; B, stellate cells in hypodermis, from 
83. 
the anal angle of a wing shown in Fig. 
generally retains its attachment to the basement membrane, 
and thus to its neighbors opposite, in those portions of the 
wings where the membranes are united: The cells thus become 
peaked in appearance. Their breadth and height will depend, 
however, on (1) the extent of the previous crowding; (2) the 
extent of the surface they are now called upon to cover; and 
(3) the width of the space they are now called upon to bridge. 
When, through excessive crowding, some of the innermost 
