THE BLACK- VEINED AND SMALL WHITES. 391 



any scruple in killing the caterpillar, and it is surely better to 

 kill one Butterfly than fifty or sixty caterpillars which it 

 produces. 



At Fig. c is shown the egg of this insect. The reader may 

 remember that, when treating of the Swallow-tail Butterfly, I 

 stated that all insect eggs were not oval. This egg is an 

 example of a considerable departure from the oval shape. 

 These eggs are deposited in small clusters, varying from two or 

 three to twelve, and they all stand upright on their bases, just 

 like a number of little bottles, being fixed to the leaf by a 

 gummy secretion. The caterpillars are hatched in about a 

 fortnight, and grow very rapidly. One of them is shown at fig. 

 a. When full-fed they ascend some convenient object, and 

 change into the pupa, which is fixed by its tail, and prevented 

 from falling by a stout silken belt passed loosely lound its 

 body. This pupa is seen at Fig. b. Its colour is grey-white, 

 with a slight dash of blue, diversified by a number of little 

 black spots. The point of the head is yellow, and so is a line 

 along the ridge of the back. 



There are two broods of this destructive insect, the first in 

 May and the second in August, so that, if its numbers were not 

 kept down by tlie ichneumon flies, we should scarcely have a 

 cabbage in England. I have dissected the larvse of all our 

 common Lepidoptera, and never found any to be so afflicted 

 with the ichneumon as that of the Cabbage Butterfly. Indeed, 

 the difficulty was to find one that was not being slowly 

 consumed by the tiny but fatal larvse of the Microgaster, 

 which has been described on page 325. 



Other details of this insect are given on Woodcut XL. Fig. e 

 representing the palpus, / the head, and g the claw of the foot. 



There are several other Butterflies which go by the popular 

 name of Whites. There is, for example, the Black-veinbd 

 White {Pieris cratcegi), which is without spots, but the 

 nervures are black. This is, in consequence, an admirable 

 insect for the study of the wings. It is a local and somewhat 

 intermittent insect, and appears about Midsummer. 



Then there is the Small White [Pieris ra-pce), a very 

 variable Butterfly, in which the male is nearly white, except a 

 clouding at the tips of the upper wing?, and a rather indistinct 



