CH. XI] B. MORPHOLOGICAL 127 



in their formation would be absolutely useless, and when their 

 movement would be of no value until it was perfected? Why did 

 it also evolve Drosophyllum, with no movement, and with two 

 kinds of tentacles ? And how did it place the tentacles in straight 

 rows, and make them all alike? Again the reply has to be that 

 morphological considerations inherent in the plant override the 

 effects of natural selection. And why so, when they must them- 

 selves have been derived in the same way? Further, how did 

 natural selection evolve, in the same small family, Aldrovanda 

 and Dionaea, with leaves that close up like a book? One does not 

 expect to find, in so small a family, such marked differences; it 

 reminds one of the Podostemaceae. The differences are much more 

 marked than in a whole large family like the Compositae or the 

 grasses. 



There is almost no end to the inexplicable difficulties in 

 structure that can be brought up for the selectionist to try to 

 explain. Here, for example, are a few picked out in hastily 

 running through the list of family distinctions given at the end of 

 my Dictionary: 



The windows in the leaves of Aponogetonaceae. 

 The complex inflorescence of Zostera. 

 The three-ranked leaves in Cyperaceae. 

 The spiral or disc-like flowers of Cyclanthus. 

 The pitcher of leaves in many Bromeliaceae. 

 The resupinated flowers of Orchidaceae. 

 The Equisetum-like stems of Casuarina. 

 Chalazogamy. 



The explosive stamens of Urticaceae, etc. 

 The integumentless ovule of Opiliaceae. 

 The tetradynamous stamens of Cruciferae. 

 The pod of Leguminosae (why not a follicle?). 

 The obdiplostemonous stamens of Oxalidaceae. 

 The cyathium of Euphorbia. 

 The explosive capsule of Impatiens. 

 The stinging hairs of Loasaceae. 

 The asymmetrical leaf of Begonia, etc. 

 The one-sided flowers of Lecythidaceae. 

 The vivipary of Rhizophora. 

 The free-central placenta of Primulaceae. 

 The corona of Asclepiadaceae. 

 The scorpioid cyme of Boraginaceae. 

 The didynamous stamens of Labiatae, etc. (why 

 do they match in several different families?). 

 The four nutlet fruit of Labiatae. 

 The pappus of Compositae. 



