Classification of Plants. 363 



little one-seeded stone fruits or druplets that adhere and 

 form an aggregate fruit. Because of these similarities we 

 classify them under the same genus, Rubus. Rubus vil- 

 losus and Rubus hispidus have many other relatives among 

 'the blackberries, raspberries, and dewberries, with distinc- 

 tive characters, but all sufficiently alike to indicate a close 

 relationship. 



If we turn to the strawberries we find evidences of 

 relationship between them and the blackberries and rasp- 

 berries, the flowers of the strawberry also having a five- 

 parted, broad and shallow calyx, but with a bract between 

 each division ; numerous stamens with slender filaments, 

 numerous carpels on a convex receptacle. Thus far the 

 resemblances are striking and afford evidence of relation- 

 ship ; but we also find some pronounced dissimilarities, 

 the carpels in ripening do not become fleshy stone fruits, 

 but dry, one-seeded nutlets, and the receptacle grows to be 

 large, fleshy, and fragrant. The relationship does not 

 seem close enough to class the strawberry under the genus 

 Rtibus, and we accordingly group the various species of 

 it under the genus termed Fragaria, on account of the 

 fragrant receptacle. 



The similarities which we find between the raspberries, 

 blackberries, and strawberries indicate a remote common 

 ancestry, and we therefore place the genera Rubus and 

 Fragaria under the same family, Rosacecz, rose family. 

 While it can be seen that a classification on such a basis is 

 natural in contradistinction to artificial, and does, to a large 

 extent, indicate true degrees of relationship, yet it must be 

 a matter of judgment as to where the lines shall be drawn 

 between species, genera, etc., which must be more or less 

 arbitrarily exercised. 



There are still more comprehensive grades of classifica- 



