90 INFLUENCE OF EXERCISE ON MAN AND ANIMALS. 
most important inquiry, without doubt, is that which concerns the 
proper structure of the vesicle, as well as the existence and 
structure of the ovum contained within it ; since it might happen 
that the ovary might contain a vesicle, but that be without ovum ; 
or else, that the ovum might never depart from the ovary, or be 
duly received by the duct ; and, lastly, that the ovum might not 
have that composition and structure fitted for fecundation by the 
semen of the male. 
It is true our examinations, being hitherto confined to aged mules, 
are not such as to warrant us in answering such questions as 
these ; at the same time, taking the case of the actual procreation 
of the mule, these questions are in truth resolved, since, had not 
matters being fitting and proper, the mule would never have con- 
ceived. 
The subject is both curious and interesting, and, being as yet 
but unsatisfactorily investigated, both needs and deserves further 
examination. 
Lecture on the Influence of Exercise on Man and 
Animals. 
[Continued from “ La Clinique Yet4rinaire” for March 1847.] 
Temperature. 
The wind is one of the greatest obstacles to freedom of move- 
ment ; it tends to fatigue a horse much in his course. It has been 
calculated that the wind opposing a horse in a gentle trot calls for 
four times the amount of force ; in a full trot for nine times ; in a 
gallop for sixteen times ; and in the race it is by no means a rare 
thing to see a horse fall in a state of suffocation after having run 
any great length of distance in the face of the wind. 
Soil. 
The influence of soil is shewn more on horses in draft. The 
weight and construction of the vehicle a horse has to draw will 
tell in deep and rough ground ; in the former in proportion to the 
impression made in it by the wheels, large wheels, from the less 
impression they make, being the best to run ; though on hard and 
uneven ground they become an obstacle to draft, from their greater 
weight. 
Carriages and Draft. 
Our engineers of bridges and causeways — whom in a paren- 
thesis we may accuse of having thrown the greatest impediments 
in the way of improvement of horse draft, by extravagantly lauding 
