SUMMARY1. The thermoregulatory response of the galago, the baboon and the chimpanzee were studied on exposure to dry bulb temperatures of up to 400 C in a temperature controlled room.2. Heat exposure caused an elevation in the respiratory frequency of all three species. The increase in the galago was significantly greater than that in the baboon and the chimpanzee.3. Heat exposure also caused an increase in the cutaneous moisture loss of the baboon and the chimpanzee but not in the galago.4. Rectal temperatures always rose on heat exposure but the animals never become hyperthermic.5. Sweat gland activity in the baboon and the chimpanzee was stimulated by the administration of acetylcholine and was blocked by the administration of atropine. Sympathetic and parasympathetic drugs had no stimulatory effect on the sweat glands of the galago.6. Local, infra-red heating of the skin of the galago and the baboon did not stimulate any sweat gland activity.7. The sweat glands in the galago and the baboon were found to be epitrichial.8. These findings are discussed in relation to the habitat of each species. They are also compared to thermoregulation in other primate species, especially in relation to the unique nature of thermoregulation in man.

Total teat number in a Large White and a British Landrace population had a modal number of 14. The trait was highly leptokurtic, indicated by the fact that 086 of the population falls within one standard deviation of the mean. There was no sex difference in total teat number, although a small but significant breed difference existed. Heritability of the trait was low, of the order of 0·10 to 0·20 based on the sire component of variance. Larger dam terms suggested a maternal effect.Severely inverted teats (nipple invisible) were observed in 0·17 of gilts. Mean number of inversions was 0·738 in the entire population but 4·01 in affected gilts. The heritability of the trait was of the order of 0·20 and a maternal component was possibly involved.Inverted teats are not distributed at random. They occur most frequently in the umbilical and anterior regions and diminish sharply in frequency towards the rear. In this study 0·97 of all affected pigs had one or more inverted teats in the umbilical and anterior regions.

Hoocrs, JonN, TervNBN, L., McGrLLIvRAy, B. J., HIr-r,v, P.G. ,A.No For personal use only.

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