Biology of I. ricinus 



305 



mouthparts. Wheler sent specimens to Lewis (1900, p. 382) to study. 

 The latter placed males and females together several times and 

 repeatedly saw coupling occur. The male crept upon the venter of the 

 female and probed about with its mouthparts, the palps being in their 

 normal position whilst being passed to and fro across the vulva " until 

 at length the female, which had remained hitherto entirely passive, 

 began to show signs of responding : a slight, but very distinct alteration 

 in colour of the surrounding parts took place, this being shortly followed 

 by a relaxation of the peculiar crescent-shaped, flap-like opening. The 

 palpi of the male were now immediately separated as widely as possible, 

 the extremity of the rostrum was inserted under the flap and gradually 

 pushed home until the entire organ was buried to its base." This union 

 lasted some hours. Lewis gives figures of the sexes thus united, and of 

 the % and <£ hypostomes in ventral and lateral aspects. 



With regard to the £ hypostome he adds : " A little below the 

 position of the last marginal teeth there are, however, what appear 

 in a dry specimen to be two reflexed teeth, one on either side of the 



Fig. 283. Hypostome of Ixodes ricinus & in ventral and lateral aspects, showing at 

 A, A 1 , the " tubular papillae " described by Lewis (1900, p. 385, PI. XXI, Figs. 4 and 5). 



median line, these being of larger size, thicker at the base and longer 

 but not so sharp, and differing also in apparent structure from any 

 others of their kind. On forcibly separating a male and female and 

 examining the rostrum of the former immediately after its withdrawal 

 from the vulva, I saw at once that these supposed teeth had increased 

 in size and now presented the appearance of flexible semi-transparent 

 tubular papillae, which conveyed the impression to my mind that here, 

 possibly, were the organs by means of which the actual impregnation 

 took place. I killed this tick without loss of time, and removing the 

 entire capitulum before it had time to dry or contract, mounted it forth- 

 with in glycerine. As thus mounted, with no preparation and no 



