614 EXPLANATION OF THE PLATES. 
FIG. 
29. Plumiform gills in the mouth of the spiracles of the larva 
of Cossus lig?iiperda. (Sprengel.) 
PLATE XXX. 
1. Brain, spinal chord and ganglions of a full-grown cater- 
pillar of Pontia Brassicce. a. The brain, b. The double 
spinal chord, c d. Ganglions with a portion of their nerves. 
2. Brain, spinal chord and ganglions, after two days, when 
the chord is shortened. 
3. . ■ when the animal is 
become a pupa. 
4. ■ when it has been a 
pupa six days. 
■ just before it assumes 
the imago. 
(1. ... . ■ — when it has become 
a butterfly. Vol. IV. p. 24 — . 
7. Intestinal canal of the caterpillar, a. Saliva vessel, b. Silk 
reservoir, c. Gullet or oesophagus, d. Stomach, eee. Bile 
vessels. /. Large intestine, g. Rectum. 
8. — — — — • after it has assumed the 
pupa two days. 
after eight days. a. Crop 
or honey-stomach, first showing by the dilatation of the 
base of the oesophagus. 
10. ■ • ' ' ■ a. Honey-stomach be- 
come a lateral appendage of the oesophagus b. 
1 1 . . of the butterfly, a. Honey-stomach. 
b. QEsophagus. c. Small intestine become very long. 
d. Rectum. Vol. IV. p. 118. 
12. Anal portion of the interior of the female butterfly. 
a. Ovaries, b. Oviduct, c. Colleterium or varnish 
secretor. d. Spermatheca or sperm receptacle, e. Part 
of the spinal chord. /. Rectum, g. A secretory organ 
filled with a thick white fluid, which is supposed to 
lubricate the passage. Voi>. IV. p. 132, 152. 
