230 W. A. CANNON 



limited to Point Cypress and to Point Lobos near Carmel. There 

 are, in addition, numerous otlier instances of limited distribution 

 of the species in the state, which would be pointless to mention. 



While the general distribution of these species may be accounted 

 for in the surface and climatic changes which have gone on in the 

 past geologic time, the actual limitations in distribution can 

 possibly be explained in another manner, namely, in the speciali- 

 zation of physiography and of climate at the present day. Taking 

 as an example of such specialization the Monterey peninsula we 

 note the following characteristics which set apart this from the 

 adjacent areas. The peninsula, about 4 miles square, is set out 

 into the ocean so that it is exposed to the full sweep of the ocean 

 winds, it is dominated by the temperature of the ocean, the 

 evaporation is the minimum amount, the fogs are frequent, especi- 

 ally in summer. As opposed to this condition we find back from 

 the shore, 2 miles or less, conditions surprisingly arid, and here the 

 influence of the sea is not so immediate as on the peninsula. The 

 peninsula is in elTect a biologic island, with barriers on either side, 

 but possessing within itself suitable conditions for the reproduction 

 development, and survival of several endemic species. Analogous 

 physiographic and climatic conditions obtain in many other 

 localities, as already suggested, and one other instance of special- 

 ization, this time climatic, and its effect on the distribution of a 

 species, will be referred to directly. 



ADJUSTMENTS TO THE ENVIRONMENT 



« 



I wish now to present briefly a few instances where the relation 

 between the species and the impinging environment is a fairly 

 intimate one. It happens, also, that the point of each turns on 

 the reaction of the species to the moisture relation, although in 

 the first instance to be given the scene is laid in the Transition 

 rather than in the Sonoran, the more arid zone. 



The fitness of the conifers in general to life in high altitudes, 

 where the evaporation rate is great and the absorption of water is 

 retarded by a low temperature, and where the total heat received 

 is relatively small in amount, is well known. Of the conifers, 



