ATTACUS ATLAS: A LIFE-HISTORY. 69 
farina is now considerably diminished ; it is still excreted, but in smaller 
quantity. Hence the forms and dimensions, and even the minute spines, 
of the tubercles, are now plainly seen; as are also the oval dark spots 
which crowd the entire skin, which I suppose to be the glands that secrete 
this flour-like substance. 
One of the larve of this age dying, I desired to inflate it for 
the cabinet; and, as a preparatory measure, dropped it into 
a sat. sol. alum. ‘The body floated half immersed; but, at the 
instant of touching the water, this waxy farina spread on the 
surface to the distance of one-sixth of an inch around the body, 
forming a pellicle; and this substance on the larva keeps it from 
becoming wet, hke a duck’s feathers. 
No farina is excreted till some time after moulting. At first 
the tubercles are seen to be polished on their surfaces, and to be 
beset. with very fine and short spines, not arranged in whorls. 
The upper and middle tubercles of the thoracic segments are 
aborted in this age, leaving only rugose scars. 
One cannot fail to remark the resemblance between the larva 
of Atlas and that of Cynthia. ‘There is the same whitish-green 
hue on the upper parts, becoming yellow-green on the lower; the 
same tendency to azure at each extremity; the same soft styli- 
form tubercles, which also are azure ; the same minute oval glands 
studding the skin; and the same clothing of white waxy farina ; 
which, in both species, becomes conspicuous in the third age, and 
is obsolescent in the latter part of the fifth. Atlas is of more 
clumsy shape, lacking the elegant fusiform outline of its congener : 
it has not the yellow extremities, nor the black specks on the 
sides, of Cynthia: but then Cynthia has no such ornament as the 
beautiful pale scarlet ring on each hindmost proleg of Atlas. Yet 
another point of agreement is the smallness of the head in these, 
compared with the same organ in the 5th age of such larve of 
Antheree as I am familiar with, as Ywma-mai and Pernyi. The 
propriety of Hiibner’s separation of Antherea from Attacus, which 
had seemed slight when grounded on the imago only, is much 
confirmed by the consideration of the previous stages. 
At the beginning of October my stock was reduced to five ; 
but all had been some time in the 5th age, and I began to look 
for the spinning of cocoons. I had assumed the successive ages 
of the larvee, throughout the Lepidoptera, to be limited to five. 
But, to my astonishment, I saw that the most advanced was 
