1. 1. Experiments were conducted on 596 young chickens to determine the importance of the phosphorus, calcium, and manganese content of the feed as factors in the resistance of chickens to the nematode Ascaridia galli. 2. 2. Comparisons were made between the numbers and lengths of A. galli from different groups of chickens given about 200 A. galli eggs per fowl. 3. 3. In four experiments there were fewer and shorter A. galli from the fowls kept on a ration deficient in phosphorus than from the control groups maintained on adequate diets. These differences were statistically significant. 4. 4. Similarly, chickens given a diet which was deficient in calcium had significantly fewer and smaller worms than did the control fowls. 5. 5. The fewer and smaller A. galli from groups of fowls fed on low phosphorus and low calcium diets are attributed to the worms' requirements for these minerals, since phosphates and calcium have been found to be among the more important mineral constituents of the ascarid body. 6. 6. The results of these experiments appear to constitute the first experimental evidence of the requirement of phosphorus and calcium for the normal growth of a nematode. 7. 7. Chickens on the phosphorus deficient diet manifested typical deficiency symptoms of general debility; similarly the fowls on the calcium deficient rations showed typically retarded growth, pliable beaks, and usually rickets. 8. 8. Results on A. galli from tests on manganese were too variable to show a constant trend. 9. 9. The resistance of growing chickens to the fowl nematode, A. galli, appears not to be affected by a deficiency of phosphorus or of calcium in the diet of the host.

DIETARY deficiencies and disease have been associated through the years. However, experimental tests of a single food deficiency on the host resistance to a parasite appear to have begun in 1926 when Zimmerman, Vincent and Ackert found that a deficiency of vitamin B (complex) lowered the resistance of chickens to the nematode, Ascaridia galli.4 Ackert et al. (1927, 1931a) presented evidence that vitamin A deficiency also was detrimental to the resistance of the fowl to this nematode. Further evidence of vitamin B (complex) as a factor in resistance was presented by Ackert and Nolf (1931b).

Summary 1. Investigations were made on effects of acetic acid and some other chemical compounds on larvae of the dog and cat hookworm, Ancylostoma caninum, in fecal-soil cultures. 2. The sources of hookworm eggs were worms in two young cats which were inoculated subcutaneously with larvae from a dog infection. Larvae were recovered from fecal-soil cultures with the aid of a Baermann apparatus. 3. Results of effects of chemicals on hookworm larvae introduced into soil cultures demonstrated that all the compounds tested, acetic acid in particular, acted to some extent upon the larvae. 4. Applications of five or 10 per cent concentrations of acetic acid to cat fecal-soil cultures for 24 hours after the larvae appeared at the surface of the culture killed over 98 per cent of the larvae in the cultures as determined by the number of surviving larvae in the control cultures. 5. Application of 10 per cent acetic acid to newly-made cat fecal-soil cultures inhibited hatching of hookworm eggs for two days, and limited hookworm survival to 2.1 larvae per gram of fecal material during the first five days of treatment. 6. The following 10 chemical compounds tested for the first time on hookworm or other strongyle larvae exhibited some lethal action: trichloroacetic acid, lactic acid, tartaric acid, citric acid, sodium acetate, calcium lactate, lead acetate, ferric acetate, manganese chloride and amyl acetate. 7. The order of highest effectiveness of eight of the chemicals tested against hookworm larvae was acetic acid, trichloroacetic acid, oxalic acid, citric acid, lactic acid, tartaric acid, ammonium sulfate and sodium hydrogen phosphate.

EXPERIMENTAL observations have shown that natural resistance of chickens to helminthic infections may be affected by genetic constitution, age and diet. Judging resistance on the basis of number and length of worms, Ackert and Wilmoth (1934) reported that a strain of heavy White Minorcas was more resistant to the nematode, Ascaridia galli, than a lighter strain of the same breed. Using the same parasite, Ackert et al. (1935) found that some lighter breeds of poultry were more susceptible than heavy breeds and varieties.

J. E. ACKERT and H. H. FURUMOTO Kansas State College, Manhattan The common cat, Felis domestica (Linne), is perhaps man's most abundant pet and doubtless his most valuable ally in controlling such vermin as mice and young rats about the premises. On the other hand, the habits of the domestic cat threaten the well-being of the home, especially of children who may play in sand and soil polluted by cats and infested with ascarid eggs or hookworm larvxe which may carry on an abnormal and harmful sojourn in the human body. This study was made to determine the kinds and abundance of helminths (parasitic worms) in the digestive tracts of a fair sample of cats in Eastern Kansas. Materials and Methods The cats used in making the study were obtained from the zoology department after the students had completed the anatomical dissections. Although no definite record as to the source was kept, most of the cats were brought in groups of two or six, from farms and villages within a 100-mile radius of Manhattan, Kansas. The stomach and intestines were removed from each cat, and the mesentery and omenta stripped off. With scissors an incision was made from the cardia to the rectum along the greater curvature of the stomach and opposite the mesenteric attachment of the intestines, after which the exposed worms were removed by forceps and placed according to habitat, in separate containers. The three distinct anatomical portions of the gastro-intestinal tract were used in segregating the parasites; thus the helminths were placed in one of three containers labeled stomach, intestine, and large After the worms were rinsed in the containers, they were transferred to vials containing five per cent formalin. Following this the vials were labeled with the specimen number of the cat and the location from which the parasites were taken; for example, Cat No. 15, small intestine. Later, the helminths were identified and recorded. Observations on Data The gastro-intestinal examinations for helminth parasites proceeded until 131 cats had been examined. Almost every cat had some parasites; only two were entirely free. This gave a helminth incidence of 99.15 per cent. Those cats having parasites in the stomach alone numbered two,

portance of protein supplements to basal cereal rations as factors in the resistance of chickens to their ascarids. In young chickens parasitized at the age of a month or so, a supplement of skim milk given on alternate days to parasitized chickens aided them in eliminating most of their worms, whereas the chickens on the same ration except for the milk retained a much larger number of their ascarids.

Summary 1. Experiments involving parastized and control fowls were made to test the tolerance of growing chickens to moderate infections of ascarids and tapeworms. 2. The criteria for judging the tolerance included growth, blood sugar level, and hemoglobin content of parasitized fowls comparable to those of the control chickens. The criteria for the tapeworm tests included also differential blood counts. 3. Chickens 23 days of age parasitized with 200 infective eggs of the fowl ascarid, Ascaridia galli, were able to tolerate infections of from one to 46 worms without manifesting definite harm from the worms in four weeks. The average of 17.9 ascardis per fowl is above the average infection in range fowls. 4. Growing chickens parasitized at 40 days of age with 200 larval tapeworms (Raillietina cesticillus) were not significantly harmed by infections of from two to 172 tapeworms during a period of eight weeks. The average of 61.5 tapeworms per fowl is more than an average infection found under conditions of general poultry production.