ON THE ERGOT OF EQUIDAE. 
Race Name 
Fore Callosity 
Hind Callosity 
Length 
Breadth 
Height 
Length 
Breadth 
• 
Height 
(a) left 
cm. 
cm. 
cm. 
cm. 
cm. 
cm. 
Kquus Grevyi 
,6 
1 ,o 
— 


ri"-ht 
I 7 
>» 
IL) J IcIL 
.o 
2, 1 
right 
1,1 
2,0 


— 

Kquus Samali- 
left 
2,0 
4,o 
cus 
right 
2,1 
4.3 

— 
— 

Equus Burchelli 
left 
2,0 
3.2 
(l5urchelli Zebra) 
right 
2,1 
3.4 
Equus Asinus 
left 
2,3 
2,4 
Afric;inus (Nubian 
right 
2,2 
2,5 
Wild Ass) 
Equus Caballus 
left 
1.5 
3P 
o,3 
2,2 
Prezwalskii(Mongolian 
right 
1,6 
2,9 
o,4 
2,1 
Wild Ass) 
Equus Heminous 
left 
4.1 
7.4 
Kiang 
right 
4,o 
7,o 
Equus Quagga 
left 
2,9 
5,o 
right 
2,8 
5.3 
In the case of the Callosities of the bastards, Professor Ewart has pub- 
lished his observations in the "Proceedings of the Royal Society of Edin- 
burgh", p. 467. He writes, "Among the Esquimaux hybrids the Callosity is 
absent ; among Mongolian hybrids it is absent on the right fore foot and 
quite small on the left ; while on the zebra hybrids it is very large on the 
hind feet." Many other zoologists have also recorded the results of their 
studies of the Callosities of the mule, eselzebroid and hinny. All these ob- 
servations point to the same conclusion that when Callosities are found on 
both fore and hind feet, they are larger on the former than on the latter ; and 
that when only one pair is found, this is always on the fore feet. On the 
contrary, when Ergots are found on all foiu' feet, they are larger on the hind 
feet than on the fore ; and when only one pair is found, this is always situated 
on the hind feet. 
Thus we see that while the histological structure of the Callosity and 
Ergot is similar, the position of the larger pair is in the one case on the fore 
feet and in the other case on the hind feet. 
