F. H. Stewart 
217 
of B and D, and all three were breathing in a rapid and exaggerated 
manner. 
On 16. iv. rat D was killed. The same nematode larvae were found 
abundant in the lungs. No larvae were found in the trachea, hver, 
heart, spleen, kidneys, stomach, intestine or in the masseter and lumbar 
muscles. 
Rat A had apparently recovered from its illness on 17. iv., rat B 
on 18. iv. 
The organs of C and D were examined by serial sections. In the 
lungs the greater part of the air vesicles were found to be filled with red 
blood corpuscles. Larvae were found in the air vesicles (PI. I, fig. 4) 
and in the bronchi of D (PI. I, fig. 8). 
No larvae were found in the other organs examined, viz. liver, 
kidneys and spleen in the case of D, kidneys and spleen in the case of C. 
As a control another specimen of Mm decumanus (albino), E, 
obtained from the same source b.9, A, B, C and Z), and five specimens 
of the wild M. decumanus and two of M. rattus obtained from the town 
of Victoria were examined. No larvae were found in their lungs. 
The rat B was killed on 22. iv. The lungs, trachea, nasal cavities, 
liver, heart, spleen, stomach and intestines were examined. No larvae 
or other worms were found. The lungs appeared shghtly fibrosed but 
otherwise normal. The rat had therefore freed itself from the parasites 
16 days after the date of the first infection and 12 days after the date 
of the last infection. 
(3) Further experiments were made to confirm the result obtained. 
On 22. iv. two white rats F and G were given l^rge quantities of mature 
eggs. Rat F was treated with the eggs of an Ascaris of the pig which 
were 80 days old. On 25. iv. the treatment was repeated. On the 
27th the rat was obviously ill and breathing at the rate of 134 per 
minute. It continued seriously iU until 4. v. when it was killed. The 
lungs were almost sohd from pneumonia and were markedly soft and 
gritty when teased. The following organs were carefully searched 
with a dissecting microscope—nasal cavities, surface of the tongue, 
trachea, oesophagus, lungs, kidney, spleen and the entire ahmentary 
tract. No nematodes were foimd with the exception of one dead larva 
(probably an Ascaris, vide infra) in the stomach, and one dead and 
partially digested larva of the same character in the rectum. 
This rat had therefore become almost completely free of infection 
in twelve days from the date of first infection and nine days from the 
last. 
