309 



normal one for our species, aiul it ^ives a sijifiiifieance to the habit 

 which cattU' have, when attacked, of rum liiiy' to aii<l staiidiii}^ in water. 



The strongest objections hitherto, in my own mind, to considering the 

 habit of enticing the animal as here described, the normal one, have been 

 the following: First, the fact that the young larva found in the 

 esophagus or uuiscular tissue has been a very smootli larva, a charac- 

 teristic which seems inconsistent with the power of clinging to the 

 tongue or penetrating the lining of the esophagus; secondly, the long 

 period from the time the egg is taken iiit(> the mouth, /. e., in the spring, 

 to the time of the i)resence of the larva as observed by Dr. Curtice in 

 the passages, as des(!ribed, this being during the months of December 

 and January. The ftgures of the embryonic larva, or first hirva from 

 the egg (see Fig. 44t'), will show at once, however, that this newly- 

 hatched larva is provided with a number of spinous points which admira- 

 bly fit it for clinging to the tongue or to the roof of the mouth, while 

 the })ecu]iar arrangement of the stronger anal hooks is admirably 

 adapted to penetrating the walls of the esophageal passages. Now 

 such a spiny creature would undoubtedly cause an undue amount of 

 inflammation in penetrating and wandering through the animal's tis- 

 sues; and we find, therefore, that upon the very first molt it loses 

 these spines and becomes almost entirely smooth, with the exception 

 of some minute spines around the anal portion. The movement of 

 this young larva in the body of the animal must be extremely slow, 

 and its development still slower, or perhaps for a time entirely re- 

 tarded. The most cursory examination of this larva in this smooth 

 second stage, however, shows that the skin is underlaid with numer- 

 ous and extremely well-developed muscular bands, which must mate- 

 rially help it to push its way through the tissues, however slowly. 



In reference to the second point, while it seems at first sight strange 

 that there should be this slow development during the nine or ten 

 months of its wandering life, we have positive evidence that such is 

 the fjict in the case already recorded in Insect Life, Vol. ii, pp. 238-9. 

 Here the extensive wandering in a child of a grub which was doubt- 

 fully referred to Hypoderma diana is given by Dr. Elizabeth E. Kane, 

 of Kane, McKean County, Pa. The case occurred in the practice of 

 Dr. Sylvanus D. Freeman, of Smethport, McKean County, Pa., who, on 

 the 22d of February, 1889, had been called to attend a child which Avas 

 supposed to be suffering from erysipelas. The child was a boy 3 or 4 

 years old, and suffered suflQcient pain to prevent his sleeping at night, 

 the cause being attributed to something working under the skin. This 

 worm, or what the mother called a " pollywog," had been first noticed 

 five months before, being then under the skin near the sternal end of 

 the right clavicle, and it had, in the five months, traveled up and down 

 the chest in front, down one arm to the elbow and over one side of the 

 back. It was only toward the time at which Dr. Freeman had been 

 called in that the serious annoyance had been caused. I was not suf- 



