286 OUR INSECT FRIENDS AND FOES 



families of more or less remarkable and 

 interesting creatures. While in the body of a 

 Tick no distinction into regions is recognizable, 

 there exist the same series of paired appendages 

 as are present in the Scorpions and Spiders. 

 The Ticks do not undergo a complete metamor- 

 phosis like that of the true insects, the larva on 

 emerging "from the egg closely resembling the 

 adult in general appearance, save that it is hexa- 

 pod has six legs. After feeding, gorging them- 

 selves to repletion on the blood of their host, the 

 larvae remain for a short period dormant, vary- 

 ing in duration in different species. They then 

 undergo their first moult and emerge from their 

 cast-off skins as eight-legged (Octopod) nymphs, 

 active, bloodthirsty, and resembling in appear- 

 ance the adult females, but with the sexual organs 

 imperfectly developed. This stage of the Tick's 

 life varies in different species from a few days to 

 several weeks, .the nymph becoming engorged 

 with blood, and, after a dormant period, under- 

 going the second moult and emerging as the 

 adult Tick. The adult Ticks gorge themselves 

 upon the blood of their host, mate, and then 

 generally quit their host, and the females shortly 

 after commence to deposit their eggs on the 

 ground or herbage, the number of eggs varying 

 in different species from ten to several thousand. 

 The dormant periods at the close of the larval 

 and nymphal stages may or may not be passed 

 upon the host, and it is in this way that the Tick 

 becomes the transmitting agent of disease, pass- 

 ing, for instance, as a gorged larva from an 

 infected and infective host to the ground, and 



