3S4 E. T. LEWIS OX :xoi>£s RELurirs (ltsx.). 



even approximately in apposition. Neumann al^o calls attention 

 to the dissimilarity observed between the rostrum of the male 

 and that of the female as being a character of this species. 



The question, however, naturally suggested it-self that if what I 

 had seen was really an act of fertilisation, a careful examination, 

 of the rostrum of the male might reveal something which had 

 hitherto escaped notice. I was encouraged in this idea by the 

 remembrance of my observation on the deposition of eggs by a 

 tick in 1892,* in the course of which I discovered the existence of 

 a new and hitherto unsuspected organ which appeared and came 

 into operation at that particular time, an observation which 

 exploded the old notion that the eggs were laid through the 

 mouth, and revealed one of the most comphcated and remarkably- 

 fascinating processes yet seen in connection with the phenomena 

 of o\"iposition. The description given of it was at the time re- 

 garded in some quarters rather as a romance, but it has since 

 been confirmed by so many independent observers as to admit of 

 no further incredulity. In the case of /. reduvius it was described 

 and figured by Mr. Wheler in Science Gossip for 1899, p. 109. 



Most microscopists are familiar with the mouth organs of ticks 

 as mounted objec-ts, but those who have only seen them as such 

 have still much to learn as to their remarkable structure, — to be 

 properly understood they must be studied in the Hving stat^. 

 Although the general features have been often described, it will 

 perhaps not be time wasted to once more call attention to them. 

 In both sexes the rostrum, as seen in profile (Figs. 3 and 5), is 

 divided into two parts, of which the lower, known as the labium 

 or hvpostome, is arme<i on its under side with reflexed spines or 

 teeth, whilst the upper portion appears to be tubular and (at 

 least in the case of the female) to contain the shafts of three 

 pairs of cutting instruments — the mandibles or apophyses — the 

 serrated blades of which extend beyond the terminal extremity of 

 the tube. From the dorsal aspect, the two sheaths or tubes are 

 seen to be of oval shape, their inner edges lying in close contact 

 and their under surfaces resting upon the upper, smooth, but 

 shghtly concave, face of the labium. Their length, when fidly 

 extended, is nearly the same as that of the labium, beyond which 

 the mandibles then project. The shape and position of the blades 

 of the mandibles are as drawn, the inner pair being grooved as 

 shown in the figure of those of Ixodes Varani in the Q.M.C. 

 * Journal B. M.S., 1892, pp. 449-54, plate vii. 



