THE ORGANS OF SPECIAL SENSE. 229 



by the frequent application of weak ointment of cantha- 

 rides. 



Verrucje, or warts, are circumscribed hypertrophies of 

 the papillary layer of the dermis, either congenital or the 

 result of dirt, or growing without any distinct cause. They 

 are often in the dog seen on the mucous membranes of the 

 mouth and prepuce where those membranes present some 

 of the characters of true skin. They may be found on 

 almost any part of the true skin, but especially affect the 

 eyelids, margins of the ears, and the lips. They can be 

 removed by excision or the application of caustics. The 

 warty growth which sometimes appears on the front of the 

 eye seems to be specially frequent in the dog. 



Dropsy of the Subcutaneous Areolae Tissue, Anasarca, 

 is in the dog seen as a result of debilitating affections or 

 local irritation. It is, however, rare in this animal, and 

 principally occurs below the jaw and belly. It requires 

 no treatment other than that for the disease on which it 

 depends. 



An acute inflammation of the skin, especially affecting 

 the head or scrotum, has been described by some authors 

 as erysipelas of the dog. Its effects extend deeper and its 

 course is more violent than eczema ; it accordingly needs 

 more active treatment, both general and local, than that 

 simpler form of disease.. It tends to extensive sloughing 

 of the parts or death from irritative fever, and is, fortu- 

 nately, but rarely seen. It most frequently affects the 

 scrotum (which see). Laulanie has noticed, associated 

 with the presence of Demodex folliculorum, a disorder 

 which he terms cutaneous tuberculosis. 



PAEASITIO AFFECTIONS OF THE SKIN in the 

 dog are numerous and of much importance. Some are 

 due to animals which permanently take up a residence at 

 the surface of the host, others to those which are only 

 temporary visitors. The former class of ectozoa comprise 

 the mange dermatozoa, scarcoptes, dermatodectes, sym- 

 biotes, and acarus ; the latter fleas, lice, ticks, and other 

 insecta, such as harvest bugs. After dealing with the 

 diseases and inconveniences resulting from these animal 



