202 
Ascaris lumbricoides 
Nine were examined on the 10th day. Ascaris lafvae were found 
in the caecum in five, in the lungs and trachea but not in the caecum in 
one, and three were negative. 
Five were examined on the 11th day. Larvae were found in the 
caecum in one, in the lungs and trachea but not in the caecum in two, 
and two were negative. 
Anatomy of the Larvae of A. suilla from the Pig. 
Unfortunately I was unable to take detailed measurements of many 
specimens owing to lack of time. The only difference noted, compared 
with larvae from rodents, consists in the fact that the excretory gland 
lies slightly further back, the nucleus being on a level with the posterior 
end of the oesophagus. 
The following are the measurements of a specimen on the 8th day 
from the lung, fixed by heat in salt solution. Length 1-5 mm., oesopha¬ 
gus 0-23, oes./length 1/6-5. 
Measurements of specimens from lung of pig on the 6th day (1) Total 
length 1 mm., maximum breadth 0-038, oesophagus length 0-176, 
oes./t.l. = 1/5-6. (2) T.L, 1mm., br. 0-038. (3) T.l. 0-8 mm., oes. 
0-15, oes./t.l. = 1/5-3. 
Note. Correction of the description of the larvae from rodents in Parasitology, 
ix. p. 155. 
The excretory gland can be identified in larvae as young as that figured in PI. I, 
Fig. 2 (from fiver of mouse 2nd—f-tli day). Even at this early stage it lies in the 
same position as later, in the left lateral fine opposite the posterior swollen portion 
of the oesophagus. The orientation of Figs. 6 and 7, and 9-12, PI. I, is therefore 
incorrect. The letters VL. should read left lateral fine, the fines marked L.L. are 
the median fines, and D.L. is the right lateral. 
Economic importance of Ascariasis in Pigs. 
Regarding the prevalence of ascariasis infection in pigs, Lynch 
(Diseases of Swine) states that “in the large packing houses of Chicago, 
Kansas City and Omaha the parasites are found in large numbers in 
nearly half of the animals slaughtered." My friend Mr A. Gibson 
kindly made an estimate of the proportion of animals infected among 
those slaughtered at the West Point abattoir, Hong Kong, and informed 
me that at least 50 % were infected. I examined 83 pigs from the 
Hong Kong dairy farm and found 24 % infected. The animals on this 
farm are kept under exceptionally sanitary surroundings and it might 
be expected that the infection would be low. 
