97 



NOTES ON COLLECTING (LEPIDOPTERA). THE EGO STATE. 



{Continued from page 70.) 



MANAGEMENT. 



Eggs should never be touched ; when, however, for convenience it is necessary 

 to remove them, as when found in Nature, or deposited in awkward or insecure po- 

 sitions in our breeding or other cages and boxes, the operation must be conducted 

 with great care, and it must be remembered that the eggs of several species, as 

 E. croceago, A. prodromaria, and others, are very soft when first laid, and that if tho 

 substance to which they are attached be even twisted or disturbed at this stage they 

 will perish, but after a little time the shells harden, and they may then with caution 

 be removed by carefully cutting out the substance to which they are fixed ; as a 

 precautionary measure it has already been suggested to line the laying boxes loosely 

 with paper, and the cages into which the perfect insects emerge should also be lined 

 with leno or gauze, not only for the purpose of cutting out the bits upon which eggs 

 may be deposited, but also that the insects as they emerge may at once crawl to a 

 position suitable for drying their wings. 



Ou removal the eggs should be placed in glass-topped boxes, which serve to secure 

 the future larva from escape, and yet allow the owner to watch progress without 

 opening or even moving the box. Beyond keeping them thus at ordinary atmo- 

 spheric temperatures, as in an outhouse sheltered from the rain and sun, and daily 

 watching them until such time as they hatch, no attention is necessary, unless in 

 some rare instances it be advisable to damp them from time to time : with eggs 

 which pass through the winter the chief precaution is, not to forget them in the 

 spring. 



Should it be desirable to get three broods of a double-brooded species, the Ento- 

 mologist may, as soon as the food-plant is coming into leaf, either " force " the images 

 by bringing the pupj© into a warm room, and so get eggs before the natural time, or 

 he may hasten the hatching of eggs by a similar increase of temperature. 



A few remarks on the signs of fertility and infertility may not be out 

 of place. Observation and experience will be the best guides, but the following 

 may assist the egg possessor to a decision : — If an egg, from having been yellow or 

 orange, change colour to any of the tints of pink, rose, or red, from having been 

 of reddish colour to any hue of lavender, lilac, purple, from white, drab, or cream- 

 coloured to any shade of brown or lead-colour, from green to red or lurid purplish, 

 or if an egg become black or uniformly darker, or if it get symmetrically marked, 

 spotted, banded, or ringed, flatten or change form without shrivelling, the chances 

 are that it is fertile, and that the natural changes are going on in the enclosed larva; 

 but if, on the other hand, the egg should show transparency at one point and 

 opacity at another for any length of time, or should go over its proper time of 

 hatching, or should curl or collapse, it may almost certainly be considered either 

 that the egg is unfertilised or that the contents have perished ; for though the 

 soft eggs of some species do shrivel to a certain extent, even though perfectly 

 impregnated, it is certainly, as a rule, a bad omen ; of course the above tests are 

 inapplicable to eggs which, like those of the Puss-moth, have rigid, opaque, and 

 coloured shells, but even here an adept will detect a diffei^ence between a fertile 

 and infertile ovum. 



