103 



There is one point regarding the larva I have not yet alluded to, viz., that 

 the hairs of the typical tubercles and also of the secondary dots are tipped with 

 globules of fluid. Similar globules may be detected on the hairs of the young 

 larvffi of Raps and of Brassies, but in Cardamines they are much larger and 

 more conspicuous, so that no doubt of the nature of the club at the end of 

 each hair is possible ; especially as they are shortly renewed if wiped off. They 

 are proportionally largest ia the youngest larva in its first skin, but more numerous 

 in the second, and still more in the third, as the secondary dots develop, and here 

 are proportionally larger on the hairs of the tubercles proper than on the dots. I 

 have no theory to offer as to the object and use of this curious provision. 



The larva always becomes restless when ready to change to pupa, and no 

 doubt at large wanders off to some secure place to undergo that change. I have 

 never found a pupa on the stem of the food plant, and a few larvae, observed at 

 lar-e, disappeared at this point of their history. Since it spends nearly ten 

 months in the pupa state, it is necessary that it should be well protected during 

 this period ; its well-known remarkable form as a pupa is no doubt protective. 



I need not describe the full-grown larva, the pupa, or the imago, as these are 

 sufficiently well-known. Among the specimens reared from the egg are several as 

 large or larger than are to be captured as butterflies, and also quite as richly 

 coloured. The males outnumbered the females by three to one, but as the number 

 reared was small this was probably accidental. 



