58 
W. F. PURCELL. 
In the secoud place^ the lateral tracheal proliferations 
{tr. prol.) have also considerably elongated, but in a lateral 
direction to form a broad Hattened lobe on each side. A 
portion of the lumen of the trachea is continued into the 
basal part of this lobe, and I have indicated the lumen by 
the dotted lines (tr. L), as far as 1 could trace it with certainty, 
but there are indications in the sections that the lumen 
penetrates even further. It is extremely difficult to ascertain 
the exact shape of the lateral ends of the lobes, as they are 
wedged in between several other tissues, and it is just possible 
that they are bilobed and not rounded as I have drawn them. 
'I’hat portion which could be followed with cei’taintyis drawn 
with plain lines, and the uncertain parts are indicated by the 
dotted outline in tig. 29. 
In the third place, a short basal portion has been added, 
forming a hollow stalk or pedicel {pad.) connecting the whole 
apparatus with the outer epithelium. This pedicel is 
supported on each side by a chitiiious rod-like thickening {rd.) 
in the form of a fold springing into the lumen from the lateral 
edges of the chitinous lining and corresponding to the “ pro- 
longeiiient chitineux” described by Schimkewitsch (’84, p. (36, 
PI. ii, hg. 6) in the adult of hipeira. 
'riie small entochondrite (b), which in tig. 28 is attached 
to the hypodermis near the extreme lateral ends of the 
spiracle, is now found a long way off from the spiracle. By 
comparing the two figures it will be seen that the ento- 
chondrite has not actually changed its position but that the 
spiracle (.sy>.) itself has greatly contracted, being now, in fact, 
less than half its former width, and thus the tissue bounding 
its lateral ends now comes to lie some distance away from 
the entochondrite. In shape this entochondrite {t., tig. 29) 
has greatly elongated. It is broader towards the ends and 
sle)iderer just behind the middle and is attached at its 
posterior end (at x) directly to the hypodermis. To the 
larger anterior portion three muscles are attached, viz. the 
anterior oblique muscle (u. oh. 'in. 10) and two other muscles, 
the medial and lateral spinner muscles {m. ,sp. m. 10 and 
