VADE MECUM. 71 



Caterpillar subfusiform, downy, sometimes tubercnlated. 

 Clirusalis angular, girted, head-case beaked with a sharp 



beak. 

 Sepp. I. ii. pi. I. ii. iv. 



PONTIA BRASSICiE, LARGE WHITE. 



Lewin, pi. 25. Donovan, v. 13, p. 446. Dtmcan, pi. 7, fig. 2. 



Butterjly. The wings above white, the primary ones of 

 the male black at the tip, those of the female with the tip, 

 two round spots behind the middle, and a clnb-shaped spot 

 at the interior margin all black. Primary wings in both 

 sexes white, imdemeath often cinereous at the base, with 

 yeUomsh tips and two irregular black spots in the disk. 

 Secondary ones, below, pale yellow powdered with black, 

 and sometimes an obsolete black spot. 



Caterpillar. Greenish, with many small black tubercles, 

 and tlu-ee pale yellow longitndinal stripes ; tail black. 



Chrysalis. Pale green, dotted with black. 



Observation. The female Butterfly of this species, and 

 probably of most others, possesses a pair of ovate CuUeteria 

 or varnish secretors, filled with a yellow fluid, which ento- 

 mologists suppose is used for gmnming tlie eggs to the leaves 

 on which they are deposited, and as a varnish in the con- 

 struction of their cocoons. It may probably serve also for 

 other purposes. This is the common large white or cabbage 

 Butterfly, so abundant in our gardens. It takes its name 

 from the plant on which it feeds, and to which it is so fatal. 

 "The larva of this and the following species," says Haworth, 

 " multiply so much in dry seasons, as to make gi-eat havoc 

 among our cabbages. Sec. Small birds destroy incredible 

 numbers of them as food, and should be encouraged. I once 



