REVIEW. 
477 
structures which are the seat of excited vital actions, and 
invariably in connection with a concentration of nervous 
matter; the operations of which create elements, that have 
to be expelled in the ratio of their production, the cerebral 
action determining the locality for the escape of them, 
and the issue occurs in the formation of horns. In the 
breeding of cattle and sheep, in order to secure a larger 
carcase and readier fattening qualities, causes a loss of these 
appendages, since the formation of fat is the disposal of 
matters that would, under other conditions, produce horns. 
This is followed by the causes of the development of tusks in 
the larger quadrupeds , and the work closes with a considera- 
tion of “ The influence of the generative system on the develop- 
ment of appendages in the lower animals” 
Thus, we think we have shown that there is much in 
Dr. Holland’s work which comes home to the veterinary 
surgeon, and that an attentive perusal of it will prove pro- 
fitable to him. We could have easily multiplied our quota- 
tions, but we are obliged to refrain from doing so. Others 
may hereafter be given. All the views of our author may 
not be in accordance with those entertained by others on 
these subjects; they will consequently awaken thought, and 
excite philosophical inquiry, which, rightly directed, will 
elicit truth. 
We close our review by the following extract : 
cc Man may err in his speculations, but it must not be 
forgotten that grave errors frequently lie near important 
truths ; and that the discovery of the latter, is often due to 
the stirring influence of the former, — the ground they break 
up, and the interest they impart to objects previously un- 
noticed. If our own labours are of this kind, they may 
have the ambiguous merit expressed by the poet : 
“ Si non errasset, fecerat ille minus.” 
