t7o Journal of Agricultural Research voi. xxvii, no. 
zero F. for the 5-day nor the one for the 10-day period produced an 
infection of the lungs of a guinea pig when fed to it in large amounts. 
The embryos held for 20 days and for 30 days below zero F. showed no 
activity after thawing. The former culture (20-day), directly after 
thawing and when no activity could be seen, was fed to two guinea pigs; 
no migration of larvae occurred to the lungs of either. However, in this 
culture there were some eggs that were in the various stages of cleavage; 
these partially developed eggs formed active embryos when incubated 
after the freezing period, and these embryos proved infective w T hen fed 
to a guinea pig. Nevertheless, the evidence showing diminishing vitality 
with lengthening exposure to low' temperatures suggests that there might 
be a decreasing ability to develop beyond the larval stages to maturity 
in the normal host, but this is uncertain. 
THE INFLUENCE OF DISINFECTANTS 
The following series of tests was made as a study of the manner in 
which the normal development of the eggs of Ascaris lumbricoides is 
affected by exposing them to chemical agents. Experiments by other 
investigators have shown that ascarid eggs are remarkably resistant. 
Several different ascarids have been used. Bataillon (j), experimenting 
with eggs of Ascaris equorum (= Ascaris megalocephala ), found that living 
embryos developed in eggs kept for six months in Fleming’s solution 
and that these embryos remained motile and intact in 50 per cent alcohol 
33% P er cent acetic acid, and 20 per cent sulphuric acid. Of the dog 
and cat ascarids, the eggs of Belascaris cati ( = Ascaris mystax) were found 
by Leuckart (6, p. 212) to develop completely in alcohol, chromic acid, 
and turpentine; Braun (2, p. 337) reports a similar resistance to those 
reagents and to a soda solution by the eggs of Ascaris canis , under 
which name he apparently includes several species. Wigdor ( 10 ) found 
that with the eggs of Toxascaris limbata nitric acid exhibited the highest 
ovicidal action of any of the acids, a 5 per cent solution destroying 5a 
per cent of the eggs, while the efficiency of sulphuric, hydrochloric, 
acetic, and oxalic acids decreased in the order given. The alkalis (slaked 
lime, caustic soda, ammonium hydroxid) w'ere devoid of effect, as were 
also metallic and other salts (corrosive sublimate, copper sulphate, iron 
sulphate, sodium fluorid, and potassium arsenite), hydrogen peroxid, 
and a hypochlorite. The embryos were resistant to alcohols up to 70 
per cent strength and to formaldehyde up to 35 per cent, but in more 
concentrated solutions and in volatile oils they either did not develop or 
were short-lived. The phenols, however, proved the most effective of 
any of the chemicals used by him, a 1 per cent solution of pure carbolic 
acid and similar dilute solutions of several commercial preparations 
entirely preventing the development of the ova. 
The eggs of Ascaris lumbricoides exhibit a resistance similar to that of 
the above-mentioned species. With regard to the effect of acids, Galli- 
Valerio ( 3) found that embryos developed in solutions of sulphuric, hydro¬ 
chloric, nitric, and acetic acids of 50 per cent or less in strength; more 
concentrated solutions proved more ovicidal, sulphuric acid being the 
most effective. Yoshida (11) found that embryos develop but soon die 
in eggs kept in 10-12.5 per cent solutions of sulphuric or acetic or 15-20 
per cent hydrochloric acid; in a 1.5 per cent solution of nitric acid they 
were unharmed. Wharton (9) states that the embryos died in eggs kept 
n 0.5 per cent hydrochloric a cid and in 3 per cent acetic acid. Of the 
