936 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVII. 



hence, in such large Floras, only the more distinct and easily recognised 

 species can be described at length, while the sub-species can only be very 

 briefly dealt with, or are perhaps merely mentioned by name. At the same 

 time it must be remembered that the sub-species are important units which 

 must be described in detail in small local Floras. Every species and sub-species 

 must receive a distinct name, while races and varieties will not be named. 

 These will merely be designated by letters or numbers. (This is, of course, not 

 in accordance with many modern Floras, in which no distinction is drawn 

 between sub-species, races and varieties, all sub-divisions of the species being 

 indiscriminately termed varieties.) 



Note 2. — The male and female forms of some organisms differ widely from 

 each other, while an organism may present an entirely different appearance 

 at different stages of its life-history or at different seasons. However great 

 such differences may be, all forms of one and the same organism must, of 

 course, be included in the same species. 



Note 3. — There is no logical ground for restricting the use of the term 

 heredity to the phenomenon of sexual reproduction only, or for considering that 

 organisms which can only reproduce themselves asexually are therefore unable 

 to constitute a true species. The words " always able to transmit " in defini- 

 tion I while indicating constancy under varying conditions of existence are 

 also intended to imply that, while organisms capable of both sexual and 

 asexual reproduction cannot constitute a species if they only transmit their 

 essential characters truly by asexual reproduction, organisms only capable of 

 asexual reproduction are not thereby precluded from forming a true species. 



Note 4. — As regards a decision of the question whether, or not, particular 

 organisms constitute a species, sub-species, 'Variety or race, the fact that they 

 are hybrids is of no significance. These words merely define groups of 

 organisms as they exist, and are not concerned with the question as to how 

 these groups originated. 



Note 5. — The words " always able et seq" in definition 1 may be considered 

 to preclude the possibility of one species arising from another, and therefore 

 not to be in accordance with modern ideas of evolution. Under the theory of 

 descent with slow modification, however, there can never be an appreciable 

 difference between the specific characters of parent organisms and those of the 

 majority of their immediate offspring, hence the parents and the majority of 

 their immediate offspring would always be included in the same species, as is 

 proposed in the present definitions. If, on the other hand, we seek the begin- 

 nings of new species in the sudden variations known as mutations, or in 

 such variations as may arise by the crossing of unlike forms, we have 

 to consider two distinct questions: (1) the status of the parent organisms 

 and (2) the status of their immediate offspring. So long as the parent 

 organisms are always able to transmit their essential characters truly to the 

 majority of their immediate offspring, they constitute a species, if, on the con- 

 trary, they are only able to produce a preponderance of new forms with new 



