DESCRIPTION OF THE CHRYSALIS. 305 



The rearing of boll- worms at the department would seem to show that 

 in loose, friable earth the passage made by the worms in their descent 

 becomes obliterated by the falling together of the earth behind them; 

 but it seems probable that, in compact soil, any larva entering the 

 ground would leave a round passage behind it. A thin film of silk has 

 always been noticed lining the cell in which the chrysalis is found. 



In addition to the prominent distinguishing point that the chrysalis 

 of Aletia is invariaby found only above ground, and is normally found 

 in rolled leaf and slight cocoon, while the chrysalis of Heliothis is in- 

 variably found only below the surface of the ground, normally in a 

 smooth shell, lined with a thin film of silk, it may be well to mention 

 the characteristic points which distinguish the chrysalides themselves. 



The pupa of Heliothis is reddish or light brown, 

 and polished, and the pupa of Aletia dark brown, 

 sometimes almost black, with the lower margin 

 of the abdominal rings, 4 to 6, of a reddish-yel- 

 low or saflron color; it is not polished, but has a 

 greasy appearance. The pupa of Heliothis is rather 

 stout, and the last segment is rounded and fur- 

 nished with two slender, straight spines. The 

 pupa of Aletia, contrary to this, is quite slender, 

 especially the abdomen; the last segment is not 

 rounded, and its tip is prolonged into a tail-like ap- 

 pendage, which bears at the tip 4 spines, the ends 

 of which are curved so as to form a loop; four sim- Fl( , 7? _p osterior end 

 ilar spines are placed transversely in a row, a little of chrysalis of Reiio- 

 in front of the terminal 4 hooks; this makes eight this from bel(m - 

 spines for Aletia and only two for Heliothis; the stigmata or breathing- 

 holes are rather conspicuous on the pupa of Heliothis, and sccarcely 

 noticeable on the pupae of Aletia. 



We insert a detailed description of the chrysalis of the boll- worm, for 

 the benefit of those interested : 



HeliotMs armigera. Pupa: Length, about 20 mm ; color, reddish brown, darker 

 to wards the head ; polished. The following particulars will be noticed when exam- 

 ined under the microscope : the head, which narrows in the region of the maxillai to a 

 rounded, somewhat elevated ridge, is covered with minute and rather indistinct 

 granulations, and has near the front a few shallow, transverse, impressed lines, which, 

 however,, do not entirely cross from one side to the other ; there are also a few irregu- 

 lar impressions on the head behind the eye, and about midway between the posterior 

 angle of the eye and the posterior margin of the head is an impressed puncture from 

 which a very short stiff hair arises, and another shallow impression somewhat in the 

 shape of a V may be found at the middle near the posterior margin ; the sculpture of 

 the thoracic segments is somewhat different from that of the head ; the whole surface is 

 closely and very finely faceted, and quite a number of irregular, shallow, impressed 

 transverse lines run over the whole surface ; the 3d ring is very much wrinkled ; the 

 surface of the abdominal rings is similarly sculptured ; the front margin of rings, 4-7, 

 is coarsely punctured; the 4th has only few of these punctures, but on the other three 

 rings they are quite numerous around the whole margin ; the front portion of these 

 punctures is deep, and they run out posteriorly more or less into a shallow, channel- 

 20 C I 



