82 DR. W. KIDD ON THE [Feb. 3; 
3. The Domestic Ox presents certain points of interest intimately 
associated with adaptive modifications, but many of the phenomena 
are evidently not so associated. Thus, along the median lne of 
the dorsal aspect of the Ox is seen a tuft, crest or mane, whorl, 
and long efficient tail, the length of the last being such as to 
reach beyond the dorsal whorl. The large hairy external ears, 
which can be flapped backwards so as nearly to reach the middle 
line, may also be included. These may be looked upon as adaptive 
modifications, existing for the purpose of defending the animal 
against injurious insects; and a few observations on several oxen 
and horses have been made as to the importance and frequency of 
these, and as to the use of the panniculus carnosus, even in this 
temperate climate. 
In moderate summer weather and an exposed wind-swept 
situation, the number of occasions on which certain oxen and 
horses flapped backwards and forwards their ears, corrugated their 
skins by the action of the panniculus, and flicked their tails 
on to their backs was observed and noted with the following 
results :— 
Tails flicked by oxen at the rate of 348, 468, 504, 540, 720, 
780, 1082 times in an hour. 
Ears flapped by oxen at the rate of 684, 816, 840 times in an 
hour. 
Panniculus acted in oxen at the rate of 984 times in an hour. 
Tail flicked by horse at the rate of 1108 times in an hour. 
A rough idea may thus be gained as to the importance of certain 
of these mechanisms for defence against injurious insects in hot 
countries, if in a temperate climate and exposed situation so 
frequent a use is made of them. 
4, The Horse also presents in the median plane several similar 
modifications, as a tuft, mane, and long bushy tail, which, when not 
docked, reaches almost exactly to the spot where the mane termi- 
nates. The panniculus mm the Horse is much more active in that 
part of the flank and in the forequarters where the tail does not 
reach than elsewhere. 
It remains only to point out the distinction maintained here 
between modifications of hair-arrangement which are themselves 
adaptive, as in the Otter, and others which are, so to speak, by- 
products of habits of the animals exhibiting them, such as whorls, 
featherings, and crests. The only meaning properly assigned to 
adaptive modifications is that such modifications are adapted for 
the needs or comfort of an animal. When they are adapted dy 
the habits of an animal, and have no thinkable relation to its 
needs, they must be classed strictly as non-adaptive phenomena. 
It should be further stated that all the phenomena referred to 
are congenital, and would seem to have an intimate connection 
with the problems of heredity. 
