216 
Development of Ascaris 
Pig B was fed between ix. and xii. 1915 in the same manner as 
pig A, on tinned milk and rice flour ; from i. 1916 onward he was fed 
on boiled rice and vegetables. Between 27. ix. and 2. xii. 1915 large 
quantities of ripe eggs from the Ascaris of man were administered to 
him on nine occasions. The age of the eggs varied from 22 to 
106 days. They also had been kept during the colder months in an 
incubator between 25° and 30° C. in a damp atmosphere. The faeces 
of the pig were repeatedly examined for Ascaris eggs but none were 
found. Between 5. i. and 27. ii. 1915, large quantities of eggs from 
the Ascaris of the pig were administered, the age of the eggs varying 
between 17 and 73 days. The faeces of this animal were again examined 
repeatedly but up to 17. iv. no eggs of Ascaris were found. 
These two series of experiments thus strongly confirmed the negative 
finding of Leuckart’s experiment with the pig. 
(2) On 6. iv. 1916 the writer took up Davaine’s experiment 
with the rat. Four specimens of Mus decumanus (albino) had been 
obtained. Their faeces had been repeatedly examined and no eggs of 
nematodes had been found. At 2 p.m. on 6. iv. ripe eggs of Ascaris 
lumhricoides from man were administered to all four rats. The faeces 
passed between 8 p.m. on the 6th and midday on the 7th were found 
to contain free larvae of A. lumhricoides. These larvae moved in a 
languid manner in normal salt solution. Eggs of the Ascaris of the pig 
were administered to all four rats on 7 and 9. iv. and to rats A, B 
and D on 10. iv. Eggs of the Ascaris of man were again given to rat G 
on 10. iv. The faeces continued to contain free Ascaris larvae. Speci¬ 
mens of the faeces were preserved in an incubator at 25°-30° C. Living 
larvae were found in these specimens after the lapse of three days. 
The experiment of Davaine was therefore fully confirmed. 
On 12. iv. a further development of the experiment took place. 
Rat C died. The writer was prevented from examining this rat or 
observing the remaining three until 15. iv. Rat C was preserved during 
the interval in an ice chest. On 15. iv. it was examined. A small quantity 
of blood had escaped from its nostrils. No nematodes, larval or adult, 
were found in the stomach or intestines. The limgs were found to be 
congested. Portions were removed and teased out in normal salt 
solution. Numerous nematode larvae in active movement escaped 
from the tissue. The fiver was also examined and a small number 
of larvae found. No larvae were found in the spleen or kidneys. 
The rats A, B and D were on this day obviously suffering from 
pneumonia. A small quantity of blood was issuing from the nostrils 
