XXIX 



marine and fluviatile lobsters and crabs have a red body colour although this 

 is hidden by a brown colour until the latter has been driven off chemically by 

 means of boiling. In relation with the change in the pigment of the eye many 

 aquatic animals which, when they occur at slight depth are colourless and 

 translucent, become red when they reach greater depths and darkness. In a 

 like manner many animals living in holes or inside plants exhibit this other- 

 wise so striking colour, such as the orange-red larvae of Cecidomya, those of 

 Trypanus Cossus L. and of many microptera as well as certain Indian snakes 

 (Uropeltidae). 



Concerning the caterpillars of Danaidae little is to be noted. Those of the 

 genus Eui'LOEA appear to indicate that this genus has become specialised from 

 the genus Danais. It has, indeed, been already noted that the colour develop- 

 ment in EuPLOEA MiDAMUs L. 9 greatly resembles the one which obtains in 

 the genus Danais and that this makes it probable that this species remains 

 in the condition — as may be met with in others — in which one sex has 

 retained the older form, while the other has assumed the later one. The 

 Danais form in this instance, therefore, must be the older one from which 

 the Euploea form has been developed. Amongst the little known Euploea 

 larvae, which, like those of the genus Hestia differ more especially from Danais 

 larvae in the long fleshy dorsal processes, occurs one, /. e. Euploea Mazares 

 Moore, in which these processes are short and straight, corresponding, there- 

 fore, with those in the Danais larvae and having presumably remained in an 

 older stage which is that of the genus Danais. In very young specimens 

 of Euploea larvae, furnished with the long processes, they are equally 

 short and straight as in the Danais larvae. But considering that, in view 

 of the small size of these larvae, in any case the processes are of necessity 

 also very short it would appear somewhat risky to draw any conclusions from 

 this fact. 



As regards the pupae of Danaidae much remains which requires elucidation. 

 Those of EuPLOEAs are conspicuous by their strong metallic lustre. Some, 

 such as those of E. Midamus L , completely resemble little clumps of polished 

 gold or silver, in others this lustre is interrupted by patches or streaks of a 

 dark or light brown or it is even more of a copper colour. At the fourth 

 International Congress of Zoologists, held at Cambridge, Mr. Edmond Bordage 

 stated that in the Mauritius he had reared in the dark larvae of E. Goudoti Bsd., 



