DISEASES OF THE SKIN. 341 



gether with all traces of inflammatory action in that organ so observable in January. 

 The earliest grub holes that I have been able to find are very uniform in size, corre- 

 sponding -with the caliber of the grubs contained in them, and had no appearance of 

 the sac which forms later. The walls were rough as if gnawed, and the hole was 

 cylindrical to near the epidermis, when it suddenly contracted. Now the freshness 

 of the wound and the absence of inflammatory action is a very good index of the 

 recent date of the wound, for when the wound is exposed to the air germs are sure 

 to enter, a sac grows and secretes pus. Were the wound of a more remote date it 

 would be of quite another character, as every pathologist will admit. Just preced- 

 ing the time when one is able to find the young warbles in the skin, that condition 

 known to butchers as "lick" appears. The "lick" is nothing more than an effusion 

 of serum into the connective tissue membrane, and is produced by the inflammation 

 set up by the wanderings of the young grubs. This effusion can also be found in 

 the walls of the oesophagus, just prior to the final disappearance of the grubs. The 

 disappearance of the " licks " from the tissues underlying that portion of the hide 

 most infested, the saddle, is followed by finding the grubs iu sacs in the first and 

 second cutaneous stages. When the sacs are well formed the " licks " have disap- 

 peared. These "licks" are said by farmers and butchers to be caused by cattle 

 licking themselves. It is easy to understand, however, that the cattle lick them- 

 selves at this time on account of the irritation produced by the grubs in piercing 

 through the sensitive skin. The appearance of "lick" in those parts where the 

 force of the tongue could not reach, as in the oesophagus, an appearance which has 

 been my guide to the grub and its vicinity, is quite good proof that the grubs cause 

 "lick." 



BUFFALO GNAT SIMULIUM PECUABUM. 



This is a small fly inhabiting the lower Mississippi Valley, and proves 

 a great scourge to cattle in that region. The term buffalo gnat is derived 

 from their supposed resemblance to that animal. It has a large hump- 

 backed thorax, with a head supplied with two antennae-like small horns. 

 It belongs to the order diptera, family nimulida:. The perfect fly varies 

 in length from 3 mui to 4.5 mm , the females being usually the larger. They 

 are characterized by their peculiar short and thick shape; the head is 

 bent under, and is nearly as wide as the very large and humped thorax. 

 The thick antenna; are composed of twelve stout joints; the four-jointed 

 palpi terminate in long and fine joints; the posterior shanks ami the 

 first joint of the hind tarsi are somewhat dilated. The free labrum is 

 as sharp as a dagger, and the very prominent proboscis is well adapted 

 for drawing blood. The insects possess no ocelli, but their eyes are 

 large. In the male they join at the forehead, but in the female they 

 are farther apart. The mouth organs of the male are not BO well devel- 

 oped as in the female, being soft and unable to draw blood. The bodies 

 of these gnats are quite hard and can resist considerable pressure. 

 The color of the southern buffalo gnat is black, but covered with grayish- 

 brown, short, and silken hairs, which are arranged upon the thorax in 

 such a manner as to show three parallel longitudinal black stripes. 

 The abdomen is more densely covered with similar hairs, and shows, 

 furthermore, a dorsal broad, whitish stripe, which widens towards the 

 posterior end. The legs are more reddish, but also covered with hairs 

 of the same color as elsewhere. The balancers arc yellowish-white and 



