Appendix 2 

 GLOSSARY 



Adiabatic. Changes in a gas that take place without addition or subtraaion of 



heat. 

 Adiabatic Lapse Rate. The temperature changes that result from alterations 



in the pressure of the air as the altitude is varied. Since these alterations are 



practically adiabatic, the changes are necessarily followed by temperature 



changes. 

 Algae. Aquatic plants, usually microscopic. For example, the green scums on 



water. 

 Amplexus. The clasping of the female by the male. 

 Analysis of Variance. A statistical procedure in which the total variance in 



a set of numbers is divided in such a way that the contribution of each group 



can be identified, measured and compared. 

 Atrium. The chamber into which the gills of a tadpole project. Opens to the 



outside water by a narrow tube, the spiracle. 

 Beta Coefhcients. The regression constant of an independent variable, 



multiplied by the standard deviation of that variable, divided by tlie standard 



deviation of the dependent variable. 

 Cercaria. One of the larval stages of a Trematode, parasites with very 



comphcated hfe histories. Cercariae develop in snails, and usually find their 



definitive hosts later by swimming in the water. 

 Chi-Squared, (;^2). A measure of the difference between the actual observations 



and values calculated on some hypothesis. 

 CiLLA. Microscopic, hair-like structures that serve to propel small animals by 



their wave-like motion, and in larger animals, move fluids over the surfaces 



of internal organs. 

 Cloaca. The common channel for urine and faeces. 

 COELOM. The main body cavity, in which many of the organs He. 

 Correlation. A measure of the closeness of the relation between two series 



of numbers. 

 Correlation Coefficient. A statistic that expresses the closeness of the 



relation between two variables, i-o is perfect agreement, o-o is complete 



absence of agreement. 

 Correlation Coefficient, Curvilinear. A correlation coefficient computed 



on the assumption that the relation between the variables can be expressed 



as a curve. 



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