172 
THE PRINCIPLES OF BOTANY. 
is invariably irresistibly impelled to ramble and do mischief, 
and is almost incessantly on the move, it is probable that 
many dogs in the above townships have received slight and 
unsuspected bites. As a means, therefore, of preventing the 
extension of the disease, 1 would most earnestly suggest that 
every dog, to which even a shadow of suspicion is attached, 
should be immediately destroyed, or kept in the most rigor- 
ous confinement for a period of at least ten months. Those 
who have once seen this truly horrible disease, or who enter- 
tain the slightest regard for public safety, will not, I am 
sure, for a moment hesitate to adopt such an easy and effec- 
tual precaution. Yours respectfully, 
Wm. Worthington, M.ft.C.V.S. 
Wigan, 17th January, 1871. 
P.S. — Several dogs and cattle which were bitten by this 
dog have since become rabid. — W. W. 
THE PRINCIPLES OF BOTANY. 
By Professor James Buckman, F.L.S., F.G.S., &e. 
{Continued from p. 79.) 
From what has been already advanced it will be seen that 
grasses differ very much in quality, presenting, indeed, various 
degrees between those that may be esteemed as highly nutri- 
tious and those which are so poor and innutritious as to be 
little if any better than weeds. 
If we inquire into the causes of these differences we shall 
find that they arise partly from the structure and mode of 
growth of the grasses themselves, and partly from the capa- 
bilities of the soil. As a rule, it may be said that species with- 
out hairiness, on the one hand, or harshness, on the other, 
and which have a green and succulent undergrowth which 
readily springs up after the hay is cut, are best. Such ex- 
amples as have soft down hairs, as Holcus lanatus , woolly, 
soft grass, are next to useless. Again, such hard, harsh spe- 
cimens as Aira ccespitosa — Tussac grass — are, as it were, 
mere woody fibre, covered with an epidermis largely com- 
posed of silica. These are only partially eaten by cattle, and 
that only in the young state. 
The Tussac grass, or Bull-pate, is an example of a species 
growing in a separate bunchy form ; these are usually use- 
less. Good species have the tendency to mix with other 
