CASE OF ANDREW MITCHELL. 203 



Upon the upper part of the large joint of the extended palpus. This 

 catching, or sudden jerk, gives to the delicate hairs or laminse a rapid 

 motion, and creates a current, by which its prey is brought within the 

 concavity they form. The mandibles above mentioned are stout, and 

 furnished with a small hook at the end, which catches at each move- 

 ment the projection u,pon the palpi above noticed. The moment an 

 animalcula touches the internal surface of the vibrissse, they close upon 

 it, and it is forthwith conveyed to the mouth and devoured. When at 

 rest, the fan-like portions of the palpi are folded, and brought into 

 contact or alongside the basal joint, in which position they cover the 

 upper part of the mouth. The body of the creature is pellucid and 

 diaphanous ; and the internal parts are plainly visible through the in- 

 teguments. One of the most striking peculiarities of this animal is the 

 mode in which the motion is communicated to the fan-like process of 

 the palpi, in order to create a current ; for in this instance, it is not 

 effected by the movement of the hairs themselves, nor by the rapid 

 motion of ciliae attached to them, as is seen in various Crustacea and 

 other insects, but by the mechanical intervention of another oral 

 instrument. The animal was kept for some time in a glass of water, 

 but died before undergoing a metamoi'phosis. 



Case of Andrew Mitchell, aged ten years, son of Robert Mitchell of North 

 Charlton, in the parish of ElU^igham, Northumberland, Shepherd, and 

 Ann his Wife. 



Fkom about the 1st of March 1839, the patient complained of pains 

 in the head, particularly on each side above the ears, and of what he 

 termed "gumbles," which shifted to different parts of his head; and 

 expressed his belief of something moving about in his head. These 

 pains and/ee/s continued and increased till between nine and ten of the 

 night of the 14th June following, when, whilst patient was in bed, an 

 insect, as hereafter described, was discharged from his left nostril. 

 Some blood followed on the day after the discharge of the insect. 



The pains and feels continued with some interruptions till between 

 five and six p. m. of July 5. following, when, whilst patient was sitting 

 in the cottage, a second insect, exactly similar to that above mentioned, 

 was discharged from the same nostril. For the first fortnight after 

 this second insect was discharged, the pains in the head, particu- 

 larly on the sides of the face above the ears, were very severe and 

 distracting. 



A third discharge of a similar bu.t somewhat smaller insect took place 

 on Saturday the 10th of August, while the patient was playing with 

 other children in an out-house, being exactly five weeks and a day 

 from the discharge of the second. A slight discharge of a tough 



