54 REPORTS ON INVESTIGATIONS AND PROJECTS. 



exposures below the freezing-point) endure the climate of the montane plan- 

 tation in Arizona at 8,000 feet, where the growing season is scarcely over 

 100 days, in which alternations of aridity and humidity are rapid and fre- 

 quent .and the winter conditions severe. Next it is seen that such plants as 

 Scrophiilaria (or fig^vort) and fragoria (wild strawberry) from New York, 

 which thrive at the montane plantation, together with plants taken from this 

 elevated region, survive and exhibit a most luxuriant growth at the maritime 

 plantation. A comparison of climatic data from the montane plantation (at 

 8,000 feet in southern Arizona) with instrumental records at the maritime 

 plantation at Carmel shows that the temperature conditions on the mountain, 

 which range between about 47° F. and 85° F. during the growing season, 

 are practically duplicated during the entire year at the maritime plantation, 

 a most unexpected similarity and one which it is believed has not before been 

 recognized by naturalists. The replacement of the summer rains on the 

 mountain by a season of fogs at the maritime plantation gives sufficient dif- 

 ference to yield some highly pronounced experimental results. Among these 

 may be mentioned suppression of reproduction in some species, stimulation 

 in others, atrophies of stems and leaves in some, exaggeration of vegetative 

 organs and multiplication and divergence of floral organs in others, accord- 

 ing to habit and physiological qualities. 



Species indigenous to the region of the montane plantation survive when 

 taken to the foot of the mountain, although never successful in making such 

 descent unaided, with two possible exceptions. Species from the arid re- 

 gions may survive in the equable maritime climate, but the fleshy succulents 

 from this region quickly perish when taken to the desert, demonstrating the 

 wide difference between the succulents of the desert (such as cacti) and the 

 fleshy plants of beaches. 



From the mass of detail included in the experimental records may also be 

 extracted the surprising fact that spineless or nearly spineless cacti (Opun- 

 tias) from Arizona develop and retain a decided armature when grown at 

 the maritime plantation. None of the attempts hitherto made to perfect a 

 theoretical conception which would be useful in interpreting the mechanism 

 of environic responses have had anything more than the most limited use- 

 fulness. The stimuli of climatic and many other agencies do not imply the 

 introduction of any strange or new substances into the bodies of the organs 

 affected. These agencies might change the dissociations in such a manner as 

 to modify the relative number of free ions and thus alter the molecular com- 

 plex of the living matter in a very important manner. The intricate play of 

 enzymatic action might also be altered, and any modification of the relative 

 reaction velocities of the more important processes might result in material 

 and permanent change, especially in those cases in which external agencies 

 interfere directly with the action of the germ-plasm. 



It is to be noted that the experimental results obtained at the plantations 

 reach their full value only when parallel analytical cultures are made in 

 inclosed chambers in which all of the environic factors may be fully con- 

 trolled and exactly calibrated. 



