Xo. 529] 



ORGANIC RESPONSE 



29 



equable maritime location do not survive when taken to 

 any of the other plantations, with the single exception of 

 Fragaria Calif ornica, the extremes of temperatures 

 being the evident limiting factor. 19 



liy the consideration of the responses of plants in the 

 various climates into which the}' may be introduced in 

 these experiments, it is possible to determine with some 

 accuracy the limiting factors acting for the exclusion of 

 the form in question. The analysis of the responses to 

 changed environment may he briefly given as follows: 



Species from locations with well-marked seasons, in 

 which there is a definite contrast between the warm and 

 dry periods or between dry and rainy seasons, show a 

 lessened tendency to sexual reproduction, and a conse- 

 quent weakened capacity to form fruits and seeds when 

 taken to locations with equable or monotonous conditions. 

 This is a fact well known to the grower of economic 

 plants, the chief examples I icing offered by bush and tree 

 fruits disseminated to the southward. Fertilization and 

 the preliminary stages of seed formation may ensue as 

 usual, but the absence of the stimulating effect of chang- 

 ing temperatures usually characterizing the close of a 

 season appears to be followed by a lack of development 

 of the fruit. Examples of this are offered by Ariscema, 

 Salomona, Sauyuisorha, Acta a. Podophyllum, Mcnispcr- 

 mum, Apios Fragaria and Phytolacca. Exceptions are 

 offered by Senecio, Oenothera (some species), Potentilla, 

 Geum and others. 



The transplantation of a species from one type of cli- 

 matic complex to another generally alters the shoot-habit, 

 or pattern of development of buds. The maritime loca- 

 tion is characterized by a profuse development of run- 

 ners and offsets, and the growth of brandies on the lower 

 part of main axis, above or below ground. In some spe- 

 cies, the main axis remains in a very rudimentary condi- 

 tion. Excellent illustrations are furnished by (Enothera, 

 Scrophularia, Dugaldca and Phytolacca. 



"See Kuckuck, P., "TJeber die EingewShming von Pflanzen wMrnierer 



