I 

 BUTTERFLIES AND MOTHS 219 



five days its first meal in many cases is the discarded egg-shell. It is, of 

 course, a most minute creature, but it speedily grows, and in the course of de- 

 velopment changes its skin several times, as it becomes too small for it. The 

 description of the larva in the List of Species is that of the caterpillar 

 in its last stage, before it becomes a chrysalis. Ah 1 larvae have thirteen seg- 

 ments, excluding the head. The last two segments, however, are so closely 

 united as to be difficult to distinguish in many cases, so that, popularly speaking, 

 we may say that we shall easily count twelve segments, excluding the head. 

 They have two kinds of legs, technically called true and false. The first three 

 pairs are the true legs, and are horny jointed affairs, terminating in a useful 

 claw. These are followed by four pairs of false legs, which are fleshy, and 

 terminate in a number of most minute hooks, with which the creature clings 

 to its support. There is also a last pair of legs on the " tail-part," called the 

 " anal claspers." 



Under the microscope or magnifying lens it will be noticed that all larvae 

 are covered with minute warts, from which spring the hair and spines, in some 

 cases so fine as to escape observation by the naked eye, and along the sides are 

 a row of circular marks called spiracles, through which the creature breathes. 



The head of the larva is another object of interest. It contains some 

 very minute eyes (ocelli), of little or no use to it ; a complicated mouth with 

 strong jaws ; a pair of small antennae ; and a spinneret the organ with which 

 its silken line, and sometimes cocoon, is spun. 



The pupa, or chrysalis, also is worth examining in detail. It is placed 

 in characteristic positions by the different species. Some hang head down- 

 wards, others head upwards ; others are supported by a girdle of silk round 

 the body, the ends being fastened to the food plant or stalk. Others are held 

 in position on the plant by a few cross lines of silk ; a few are hidden in a cocoon, 

 or sheath, made by bringing together the surfaces of blades of grass, or by 

 rolling up a leaf. Again, they differ much in shape and colour : whilst some are 

 green and quiet in tone, looking exactly like a portion of the plant they repose 

 upon, others are of noticeable colours, even covered with gilt or silver metallic 

 markings, which glitter in the sun. All these are points upon which the 

 identification of different species is based. While some butterflies emerge 

 in ten days or a fortnight, some of the moths remain for years in the pupal 

 stage. 



With regard to the imago, or butterfly itself, the young student must notice 

 first of all the wings, divided by ribs or veins. Seen under the microscope, the 

 wings are found to be covered with myriads of scales or " feathers," arranged 

 in rows, not unlike the tiles upon a roof. These will be found to be of varying 

 shapes in the different species ; but, in addition, the males of many kinds have 

 special scales or plumes, and I believe that the theory has been definitely 

 proved to be a fact, whilst this very chapter was being written, that these 

 plumes are scent organs, and emit a scent, much like that of different flowers, 

 which is highly attractive to the females. 



