THE ENTOMOLOGIST. 495 



we find a short, truncated, conical, suctorial tube. The 

 length of this tube is -^^^ inch, the diameter at the base 

 is 8T5 inch, and at the orifice j ^^c inch : it appears perfectly 

 smooth, and is very thin at the mouth, but evidently firm and 

 strong. Within the orifice of this tube there are two 

 elliptical sponge-like bodies, with somewhat corrugated or 

 obscurely transversely striated surfaces ; each of these organs 

 is provided with a basal ligament, which may be traced 

 backward for a short distance, when it is seen to terminate in 

 a muscular fasciculus of about the same length as the 

 ligament. This structure irresistibly suggests an action 

 within the short tube, similar to that of a mechanical piston. 

 Such an organ applied to one of the sudoriferous ducts 

 would be admirably adapted to exhaust its contents by 

 suction for the nutrimentation of the insect. The conical 

 form of the suctorial tube would adapt it to any variations 

 that might occur in the diameters of the sudoriferous pores. 

 The spiral ducts in a fine wet preparation of the human 

 scalp in my possession measured tuVji inch in diameter, 

 expanding slightly at their external orifices, so the suctorial 

 tube of the insect being t^W i"ch at its orifice and -g^-j. at its 

 base would scarcely ever fail in adapting itself as a suctorial 

 organ to the sudoriferous pore from which it might choose to 

 extract its contents. The application of the sucking apparatus 

 of the insect to the perspiratory pores of man is suggested by 

 Swammerdam, and he describes the organ by which he believes 

 it to be effected as "a proboscis or trunk, or, as it may be 

 otherwise called, a pointed or hollow aculeus or sucker." 



When the learned author described the entrance into 

 the gullet as absolutely closed, it is probable he had dis- 

 covered by dissection the two little masses within the 

 sucking-tube of the creature, and not being able to see their 

 ligamentous and muscular appendages he considered them as 

 impassable obstacles to entry of nutriraental matters. I have 

 not discovered in the specimen under consideration any 

 organism the shape of the " proboscis or trunk, or, as it may 

 otherwise be called, a pointed or hollow aculeus or sucker, 

 with which it pierces the skin and sucks the human blood." 

 As described and figured by the author in tab. i. fig. 4 a, as 

 very little exceeding one of the adjacent hairs in diameter, 

 such an organ would be quite incompetent to imbibe a single 



