No. 496] A.'il'ECT^ OF THE SPECIES QUESTION 227 



peaiiiig ill one generation or perpetuating themselves 

 through several generations, according to the number, 

 the force, the duration of the causes which united to 

 form them, etc., according to the nature, the disposition, 

 the customs, so to speak, of each i)laiit, for it is to be 

 noted that some families do not vary except in the roots, 

 others in the leaves, others in height, pubescence, and 

 color, whereas others change more easily their flowers 

 or their fruit. 



It is difficult to define a primitive species and which 

 those are which have originated by successive reproduc- 

 tion or been changed by accidental causes. It is without 

 doubt for this reason that we do not find nowadays a 

 number of plants described by ancient botanists; they 

 have disappeared, either by returning to primitive forms 

 or by changing their form in the multiplication of species. 

 For this reason the ancients knew fewer species ; time 

 has brought novelties ! And for the same reason future 

 botanists will be overwhelmed by the number of species 

 and be obliged to abandon them and be reduced solely 

 to genera! 



From Lamarck, Encyclopedic Methodique, Vol. 2, 1786. 

 Species; in botany as in zoology, a species is neces- 

 sarily constituted of the aggregation of similar indi- 

 viduals which perpetuate themselves, the same, by re- 

 l>roduction. I understand similarity in the essential 

 qualities of the species, because the individuals which 

 constitute it offer frequently accidental differences which 

 give rise to varieties and sometimes sexual differences, 

 which belong however to the same species, as the male 

 and female hemp, in which all the individuals constitute 

 the common cultivated hemp. Thus, without the con- 

 stant reproduction of similar individuals, there could not 

 exist a true species. 



From Rees, Abraham, The Cyclopaedia, Vol. XXXIIT, 

 1819. 

 Species of Plants, in Systematic Botany, appear, as 



