Marvels of the Universe 



8r 



Photo fty] 'S- ifain, F.E.S. 



GLOW-WORM CHRYSALIS. 



The chrysalis shown is a male, as indi 

 cated by the rudiments of wings hanging 

 from behind the head. 



most segment of all the grub can protrude at will a bunch of 

 white fleshy points. The brush so constituted has a double 

 use : when the insect has got smeared with the tenacious slime 

 poured out by slugs and snails it uses this brush to cleanse itself 

 with. The second use is in climbing over the smooth, slippery 

 shells of snails in order to attack the gliding snail from behind 

 the head. Its fine thin legs do not afford it a very powerful 

 hold in such situations, but by pressing this brush against the 

 shell it obtains additional support and is prevented from 

 slipping back. The head of the grub is not visible in the 

 photograph, for, except when it is feeding, it keeps its head 

 retracted under the shield which forms its first segment. 



When the grub has reached the full size it becomes in- 

 active, and lies on its side in a somewhat contracted condi- 

 tion. Then the skin begins to split along the side just behind 

 the head, and a creature of somewhat different form is 

 disclosed. By alternate contraction and expansion of its 

 segments it withdraws itself from the grub skin, and shows 

 that it has reached the chrysalis stage. In the chrysalids of 

 most insects there is no apparent distinction between the 

 males and the females : the external sexual characters are not 

 revealed until the final (usually winged) stage is reached. 

 But owing to the great difference, already indicated, between the mature male and female Glow- 

 worms, a similar difference is shown by the chrysalids : the male chrysalis, as seen in our photo, 

 having the rudiments of wings in th'eir wrappings showing plainly at the sides behind the head. 



The Glow-worm remains in the chrysalis condition only about a fortnight. At the end of this 

 time, during which a won- 

 derful process of develop- 

 ment has been going on 

 within the chn,-sahs skin, 

 the latter splits and there 

 walks out the complete 

 insect. If the chr^'salis 

 was that of a male, the 

 change is very great, for 

 the jointed upper surface 

 visible in the grub is 

 now concealed by a pair 

 of semi-transparent wings, 

 which are folded up neatly, 

 and in turn hidden when 

 the insect is at rest by 

 a pair of thin, homy 

 wing-covers. These at first 

 appear to be too short to 

 cover all the soft body, 

 but this soon contracts [*." ■'''"■"■ <-■"'•'■"•"»■■ 



., , . THE GLOW-WORM'S MYSTIC LIGHT. 



until the wmg-covers cover ^ , ,,,,,,, ,^, .l iuju 



A view in a Surrey lane, with the hedse-banks lit up by Glow-worms that tiave climbed the 

 all, herbage. In some favoured places they are specially abundant. 



