I884.J 
549 
Analyses of Books * 
contagion for so long a time after they leave the infedted district ; 
and it surely is not less difficult to understand why the cattle 
really sick of this contagious disease do not convey the contagion 
to others.” 
The next subjedt is poultry-cholera, which has been submitted 
to experimental investigation. It appears that the immunity 
gained by inoculation is retained in most cases during the entire 
lifetime of a fowl. Contrary, however, to what seemed at one 
time probable, the offspring of insusceptible fowls does not 
possess any special immunity. The importance of this disease 
may be judged from the fadt that the losses which it occasions 
certainly do not fall short of ten millions dollars annually ! 
Certain recent results on the comparative efficacy of disinfec- 
tants are quoted, from which it appears that mercuric chloride 
(corrosive sublimate) is facile princeps. 
Among the diseases of sheep must be mentioned that pro- 
duced by the “ screw-worm,” the lava of a Lucilia, which some- 
times oviposits in the nostrils of persons sleeping in the open 
air, with even fatal results. 
The total loss in the United States from the diseases of 
domestic animals is fearful to consider. Perhaps the knowledge 
of this loss, and of the necessity of studying all branches of the 
subjedt thoroughly, renders the pradtical American public less 
susceptible than that of Britain to that epidemic lunacy known 
as Anti-vivisedtionism ! 
In the botanical report some interesting matter is brought for- 
ward. There appears in the West to prevail the notion that 
wheat, in unfavourable seasons, will turn to “ cheat ” ( Bromus 
secalinus), and that a head of wheat and another of cheat may 
even grow upon the same stalk. The report is illustrated with 
twenty-five well-executed plates representing different grasses. 
From the report of the Entomologist we learn that our common 
“ cabbage white ” ( Pieris rapce), though only introduced into the 
western hemisphere about 1856, has already spread from Canada 
to the Gulf of Mexico, and proves more destructive than any 
American Pieris. 
Pieris monnste , another cabbage destroyer which occupies the 
more southern States and spreads to the West Indies, Guiana, 
and Brazil, sometimes travels in swarms of many thousands, 
keeping at about 15 to 20 feet from the earth. They are, 
notwithstanding, shy and difficult to capture. 
P . oleacea, a native of the more northern parts of the States, 
is noted for its pugnacity. Sometimes a group of a dozen will 
engage in a “ free fight ” with such eagerness that a bird or a 
dragon-fly approaches unobserved and makes havoc among the 
combatants. 
The remedies against insedt pests require much further study. 
Some species resist pyrethrum, quassia, nitrate of soda, turpen- 
tine, carbolic soap, coal oil, salt, lime, red pepper, Scotch snuff, 
