中国石龙子热生物学的研究

通过研究中国石龙子选择体温，临界温度与实验温度对该种的体温，疾跑速，摄食量，食物通过时间，表现消化系数，同化效率和生长的影响发现，中国石龙子选择体温３１．２℃，临界高，低温分别为４２．３和６．３℃，恒温室内中国石龙子的体温与实验温度接近，温度对中国石龙子的疾跑速有显著影响，３４℃中动物疾跑速最高，过高或过低实验温度中的动物疾跑减慢，温度对中国石龙子食物通过时间，单位体重摄食量，粪尿能值，表观消化系     

SOME ASPECTS OF THE BEHAVIOUR OF THE WATTLED PLOVER AFRIBYX SENEGALLUS (LINNAEUS)

The question of how aridity might influence avian clutch size, through the influences of rainfall seasonality and environmental stochasticity (unpredictability), has received little attention. A marked east-west gradient in aridity across South Africa provides a unique opportunity to test for such influences. Using an extensive collection of nest records for 106 terrestrial bird species from the South African Nest Record Card Scheme, we tested three predictions related to rainfall seasonality and stochasticity. Analyses were conducted at two levels, the first examining each species independently, and the second grouping species into five dietary guilds. The first prediction, that clutch size should generally increase with higher rainfall seasonality (i.e. higher seasonal fluctuation of food availability), was supported, particularly in the most arid environments where food abundance is more closely linked to rainfall. Controlling for rainfall seasonality, the second prediction, that clutch size should generally decrease as a bet-hedging strategy in arid, stochastic environments, was also supported. Although the timing of the rainy season differs among regions in South Africa (winter, early summer, later summer, year-round), birds primarily nest during spring. The relative timing of rainfall and breeding is expected to have different consequences for seasonal variation in clutch size among rainfall regions. The third prediction, of different patterns of seasonal variation in clutch size between rainfall regions, was also supported. In the winter and early-summer rainfall regions, early-nesting birds (breeding with or soon after the rains) generally had a larger clutch size than late-nesting birds. In the late-summer rainfall region, early-nesting birds (breeding well before the rains) had a smaller clutch size than late-nesting birds.     

SOME ASPECTS OF THE MORBID ANATOMY OF PLANTS

The anatomical modifications in the tissues of plants caused by the action of gall-inducing fungi and insects are illustrated by a number of examples, and compared with those produced by various processes of regeneration and wound healing or by factors that lead to anatomical changes without the intervention of wounds, such as nutrition, humidity, and the like. It is concluded that all living cells have the potentiality to react to various stimuli by hypertrophy, hyperplasy, or the development of meristeroatic tissues, and that the pre-existing meristems are not, of necessity, primarily implicated in gall formation.     

SOME ASPECTS OF THE BREEDING BIOLOGY OF PLANAXIS SULCATUS (BORN) (GASTROPODA: PLANAXIDAE)

Sex ratio and breeding habits of Planaxis sulcatus were studiedfor Japanese and other Indo-Pacific populations. On the coastof the Kii Peninsula, Japan, the gonad of P. sulcatus is developedfrom June through August, when pairing of the snails is observed.The females contain embryos in their brood pouches and releaseveligers. New recruits appear in autumn, grow during the nextspring and summer, and merge with the older-year cohort in sizein early autumn. The position on the shore of the first-yearand the older-year snails is lower in spring and early summerthan in other seasons. Sex ratio was significantly differentbetween populations, seemingly due to different percentagesof large snails which were mostly females. Inspection of thesamples from a wider geographic range, from Japan to India,detected various sex ratios among the localities; females weredominant in the samples composed exclusively of large individuals.The most developed embryos in the female brood pouches wereveligers. Parthenogenetic development and rearing of embryosup to crawling juveniles, which have been reported for the populationsin the inner Arabian Sea, does not seem to hold for these otherIndo-Pacific populations. (Received 20 February 1996; accepted 8 July 1996)