Biology of I. ricinus 307 



copulate and that $s may copulate several times; moreover that $s 

 will only attach themselves to a host when fertilized, i.e. during or after 

 copulation. The last statement requires confirmation. This author 

 (p. 217) denies that the penetration of the </ mouthparts into the ? 

 genital orifice (what we term coupling) represents coitus. On examining 

 a J which had been coupled for an hour with a £, her gonoduct was 

 found to be empty and no spermatophore was found in the £ excretory 

 ducts. That coitus should take place by means of the mouthparts of 

 the </" is difficult to understand because (a) the <$ mouthparts cannot be 

 brought in contact with the </" genital orifice so as to receive the sperm 

 therefrom ; (b) the structure of the £ mouthparts shows no adaptation 

 for this function ; and (c) the £ mouthparts are immediately introduced 

 into the vulva when the sexes meet. On one occasion what appeared to 

 be true copulation was observed : a coupled pair had been observed for 

 upwards of an hour when the </■ was seen to suddenly withdraw his 

 mouthparts from the vulva and advance bis body along that of the $, 

 gripping her anterior pairs of legs and body, thus bringing the sexual 

 orifices into apposition. The </" remained about two minutes in this 

 position, then retreated to his original position and pushed his mouth- 

 parts forward to the anterior border of the vulva "as if he were pushing 

 something in." The movement was repeated about 20 times, after 

 which he again introduced his mouthparts for about 15 minutes and then 

 finally abandoned the female. Samson assumes that the </ emitted a 

 spermatophore when the genital orifices were apposed, and that it pushed 

 it home with its mouthparts so that it should not slip out again. 

 Coupling, therefore, would only serve to keep the sexes together, 

 the introduction of the <$ mouthparts serving to enlarge the % parts 

 for the reception of the spermatophore. Samson does not state that 

 the % was subsequently examined for the presence of a spermatophore 

 which, unfortunately, robs the observation of a considerable part of its 

 value. 



Samson does not refer to the collapsible organs situated near the 

 base of the </" hypostome and which were described by Gene' and 

 especially by Lewis (vide supra). We shall seize the earliest opportunity 

 that offers to study these organs in living ricinus in the hope of being 

 able to determine their function. 



It is obvious from the foregoing that the process of copulation in 

 ticks requires further study. We prefer the term coupling to that of 

 copulation when referring to the condition when males attach themselves 

 to females by introducing their mouthparts into the vulva, this in the 



