C. Warburton 335 
Hypoderma larvae have often been found attacking man and their behaviour 
in such cases is very instructive. In 1886 Prof. W. M. Schoyen collected a 
number of instances, which had occurred in Norway during the previous 
hundred years, and though at that date our knowledge of the larvae of the 
two species was very defective, Schoyen states in a letter to Riley in 1891 1 that 
he had himself seen many of the larvae in question and that they were un¬ 
doubtedly Hypoderma larvae “sine dubio—H. bovis .” He continues: “As a 
rule they have undertaken long ramblings under the skin, always in upward 
directions, previous to their appearance through an opening in a tumour on 
the upper part of the body (head, neck, shoulders, etc.). All of them lived in 
this manner for months and came out in the course of the winter months 
(February or so) but were always still much too young to be hatched. However 
I have no doubt at all that they belong to H. bovis , as it is especially in those 
persons who take care of cattle in the summer months that such grubs are 
to be found during the winter. It is evidently the smell of cattle which 
attracts the bot-fly to them.” 
Two cases are so fully authenticated that a more detailed account of them 
may be given. In 1889 Dr Elizabeth R. Kane communicated to Riley the 
following facts 2 . On February 22 Dr S. D. Freeman of Smethport, McKean 
County, Pa., was called in to see a small boy three or four years old. He was 
at first unable to go but sent his assistant, who found the patient’s ear greatly 
swollen and threatening erysipelas, though there were no constitutional 
symptoms. Dr Freeman was again sent for a few days later. On Feb. 28 the 
ear swelling had subsided, but a red line of inflammation went up under the 
eyelid and then down the cheek which the doctor lanced, and from which he 
extracted a living grub about J inch long. He was told that the eye had been 
entirely closed for 24 hours. 
. m °ther who called the grub a “pollywog,” said she had first noticed 
it five months previously. It was then near the sternal end of the right clavicle. 
Thence it passed, appearing as a tiny lump followed by a red track, down and 
up the chest, down one arm as far as the elbow, then up and over the shoulder 
and part of the back, from which it had travelled to the ear, never crossing 
the median line. Sometimes it had “pointed,” and seemed about to come 
out, but it presently resumed its wanderings. Until the last few weeks the 
child had shown little uneasiness, but of late he had been unable to sleep. 
The mother believed that the grub travelled at night, for she never noted any 
advance during the day time. Dr Freeman writes: “ I have positive knowledge 
f of its movements, having just seen the track over the scapula, then up the 
neck to base of ear which was enormously swollen, from there to the outer 
corner of the eye, which was entirely closed, then to the middle of the cheek 
where it was plainly felt, and the opening made and expelled.” The grub was 
sent to Riley who in the then state of knowledge was unable to identify it 
with certainty, but doubtfully attributed it to H. diana , which infests deer. 
1 Insect Life, iv. p. 275. z /&, n . p. 238. 
