3i6 



Marvels of Insect Life. 



The aquatic podura is the Httle bhie-black creature that ma}^ often be found 

 chistering on the surface of stagnant pools and puddles. A somewhat similar 

 Insect, so far as shape is concerned, but white in colour and without a spring , is the 

 dunghill lipura. Its white colour is due to the fact that it lives beneath the soil, 

 where it feeds upon fleshy roots. It is about a tenth of an inch in length ; and a very 

 common species. An allied species, the seaside lipura, is lead-coloured, and found 

 upon seaweed and in rock crevices along the seashore between high- and low-water 

 marks. When the tide is in its hiding places are, of course, under water, but as 

 a rule the Insect appears to keep its body surrounded with air, which enables it 

 to breathe. Another species, white and eyeless, is found in caves. 



By some authors the spring-tails are held to be a connecting-link between 

 the Insects and the class represented by the centipedes and millipedes. 



Earth- Measurers. 



This name in a Greek form ^ has been 

 given to a large family of moths with long and 

 slender bodies and broad but fragile wings. 

 Properly speaking the name belongs to the 

 caterpillars of these moths, for it was their 

 peculiar form and manner of progression 

 that suggested they were engaged in 

 measuring the distance travelled. This 

 peculiarity is due to the situation of their 

 clasping temporar\- feet. They have the 

 usual six horny permanent legs placed on 

 the first segments of the body behind the 

 head ; but the soft temporary feet, that do 

 not appear in the winged stage, instead of 

 supporting the middle of the body as in 

 other caterpillars, are reduced to a single 

 pair and placed far back, just in front of 

 the tail claspers. In most other cater- 

 pillars there are four pairs of these in 

 addition to the tail claspers, and progression is effected by increasing and 

 reducing the distance between these middle feet. In geometer-caterpillars 

 the true feet are at the front end and the clasping feet at the other 

 end, so that in order to go forward the caterpillar has to take hold 

 with its fore-feet and, cm-ving its body into a great loop in the middle, bring 

 its hind-feet close up to the others. Taking hold with the claspers the loop is now 

 straightened out and the body extended to its full length, where the fore-legs again 

 take hold. In this fashion at every step it takes it covers an extent of surface 

 equal to its own length, and does it with an air of deliberation that is quite the 

 opposite of the hurried movements performed by many other caterpillars more 

 liberally furnished with clasping feet. 



Relying as they do upon these claspers for their principal support, the geometer- 



^ GeometrcC. 



Photo by] 



Spring-tail Leaping. 



[£. Slep, F.L.S. 



The lead-coloured tonioccnis is represented as in the act of 

 leaping. The spring, it will be seen, is now fully e.xtended, 

 but before the Insect has reached the ground again it will be 

 folded forward with the fork between the legs. The photo- 

 graph is thirteen times the Insect's actual size. 



