The Scottish Naturalist. 59 



expressive of genesis, and surely there is ample sufficiency for the 

 purpose, biogenesis, abiogenesis, epigenesis, parthenogenesis, pan- 

 genesis, gamogenesis, agamogenesis, &c. Or take such a word as 

 " Zooid." It is the generic term for the "individuals of com- 

 pound organisms," whether these individuals be produced by 

 gemmation or by fission, and whether they remain attached to 

 each other or become free. But when the separate Zooid is an 

 Actinozoon, it goes by the name of a "polype ;" when it is & Poly- 

 zoon, it is called a " polypide ; " and when it is a Hydrozoon, it is 

 known as a " polypite." Or take the words expressive of the cup 

 and the bell forms. The cup that contains the polypite of an 

 Actinozoon, and the cup that contains the polypite of the Sertu- 

 larida, are not designated (as probably enough they would have 

 been in botany) by the same name, but the one is a " calice " and 

 the other a " hydrotheca ; " while " calyx " is the name reserved 

 for certain of the Infusoria and of the Echinodermata, and " necto- 

 calyx " denotes the swimming-bell of certain of the Hydrozoa. 

 Indeed, almost every separate class in Zoology has its distinctive 

 technical names, and there is no hesitation in introducing new 

 words when new facts are discovered. This is, certainly, as it 

 ought to be ; for if it is necessary in science to observe minutely 

 and to maik specific differences, it is equally necessary to embody 

 the differentia in an appropriate term. 



II. But the converse of the foregoing rule holds, and, if it is 

 proper that every separate thing should have a separate name, it is 

 proper also that every separate name should have its own distinc- 

 tive meaning. 



This rule may be infringed in two ways : (1) when a technical 

 term is employed both in a general and a special signification ; (2) 

 when the same technical word is applied to various different things. 



A good example of the first infringement is the word " adnate." 

 This, in botany, is used in a general sense as a synonym for 

 adherent ; and it matters not whether the adherence be that of 

 calyx and corolla, or of corolla and pistil, or of any other parts ; 

 and it has also a narrower and special use as applied to anthers. 

 Again, the word " cell " has, in botany, a general and two special 

 significations. It should in strictness be confined to the anatom- 

 ical plant-unit ; but it has also two specialised uses, as referring to 

 the anthers and to the ovary, which might easily enough be 

 avoided if the term were replaced by such words as "sac," 



