270 Proceedings of Indiana Academy of Science 
warmth and moisture are essential environmental conditions for the 
development of these worms. The total number of hogs examined was 
1,458. Of these 780 were found affected with lung-worms, which gives 
an average of 53 per cent for the entire year. 
FREQUENCY. 
In this experiment, the lungs of four hogs were examined, which 
showed average infestation. These hogs are indicated respectively as 
A, B, C and D in table 2. In the lungs of hog A, three lesions were 
found; two in the right and one in the left lung. These lesions were 
carefully excised and dissected in physiological salt solution, in which 
the worms were counted. Like procedure was followed in the case of 
the other lesions, and the numerical results obtained are shown in the 
table. Certain facts that are thus brought out might be emphasized: 
first, the size of the lesion is but a rough index of the number of 
worms it contains; second, the right lungs are more often affected than 
are the corresponding left lungs; third, the ratio of males to females is 
approximately one-half. 
TABLE 2. 
Lung Worm Count in Affected Hogs. 
Hog Lung Lesion Size of Affected Area Females Males &% of Males 
Right 1 31 X 17 mm. 18 10 700 
A 7 2 35 X 18 mm. | 62 22 34 
Left 3 37 X 20 mm. 47 27 .57 
B - 4 40 X 35 mm 32 18 56 
Right 5 30 X 15 mm 57 33 56 
c : th, 35 X 22 mm. 28 17 75 
Left 7 34 X 20 mm. 42 24 56 
= 8 27 X 15 mm. 51 20 .39 
D Right 9 36 X 19 mm. 54 25 46 
# 10 18 X 12 mm. 12 5 41 
Hog A contained 186 worms. 
Hog B contained 140 worms. 
Hog C contained 111 worms. 
Hog D D contained 167 worms. 
Average of males 51%. 
In this count no attempt was made to separate_the species of lung-worms. 
DIAGNOSTIC SYMPTOMS. 
Unless they occur in very large number, lung-worms give little 
indication of their presence. The first symptom is a dry, husky cough, 
accompanied with an arching of the back. Frequently, there is a pro- 
fuse discharge from the nostrils and eyes, and the membranes of these 
are pale. Young pigs that harbor this parasite show a general un- 
thriftiness, anaemia, and looseness of the skin. In extreme cases, vomit- 
ing and diarrhoea may also occur. It should be borne in mind however, 
that all these symptoms are obscure and of too general application to 
be of much value. For example, a post-mortem examination of several 
pigs, that had evinced typical lung-worm symptoms, brought to light a 
heavy infestation of Ascaris suilla. These worms were present in such 
