IXODID.E 361 



may only take eight weeks. In the case of the Bont tick a single 

 female will deposit 15,000 or more eggs. The process of egg-laying 

 is described as follows by Mr. Wheler : " When egg-laying is about 

 to" take place, the head is further depressed till it rests close against 

 the under side of the body. In this attitude the end of the rostrum 

 actually touches the genital orifice, the palpi being at the same 

 time widely opened out. Behind the head and from beneath the 

 shield at what for the purposes of explanation may be described 

 as the back of the neck, a white, perfectly transparent, delicate 

 gelatinous membrane is brought down through inflation, either with 

 air or with a transparent fluid, above the head, which it temporarily 

 conceals. The end of this membrane terminates m two conical 

 points which appear to be covered with a glutinous secretion, and 

 at the same time an ovipositor of a somewhat similar character, 

 but only semi-transparent, is pushed forward from the genital 

 orifice. This latter is a tube, within which is the egg. As the 

 ovipositor projects it turns itself inside out, like the finger of a 

 glove, leaving the egg protruded at the end and lying between the 

 two finger-like points of the membrane. The membrane and the 

 ovipositor are then withdrawn each from the other. The egg 

 adheres to the former, which collapses through the withdrawal of 

 its contents, dragging the egg forward and depositing it on the top 

 of the head. Neither legs, palpi, nor the organs of the mouth take 

 any part in oviposition, but after the collapse of the membrane the 

 palpi are closed and the head i^ raised, by which action the egg is 

 pushed forward to the front edge of the shield, forming in time an 

 adherent mass of eggs, which are deposited in front of the tick." 



The egg gives rise to the larval form, the so-called " seed-tick " 

 stage. At first these minute specks are pallid and soft, but they 

 soon harden and darken in colour. These larvae are six-legged and 

 soon crawl up grasses and various plants, and there await a passing 

 host, waving their two front legs in the air and becoming attached 

 by this means. The larval ticks feed upon the blood of the host, 

 and when repleted fall to the ground, the body becoming inflated in 

 the meanwhile. These larvae may remain on the host only two 

 days, or they may remain much longer. Eventually they moult on 

 the ground, and change to the nymph or pupal stage, which has 

 four pairs of legs. This pupa acts just as the larva, crawls up 

 plants and waits to regain the host. After a time the nymphs, 

 having gorged themselves with blood, fall off and remain on the 

 ground for nearly three months ; they then moult and become adult 

 males and females. In about ten days they assume their normal 



