G. GENERAL NATURAL HISTORY AND ZOOLOGY. 263 



G. GENERAL NATURAL HISTORY AND ZOOLOGY. 



EFFECTS OF SEASO^TS ON THE DISTKIBUTION OF ANIMALS 



AND PLANTS. 



As a modern illustration of what may have produced some 

 of the earlier changes in the distribution of organic forms, an- 

 imal and vegetable, Professor Shaler makes a communication 

 to The American Naturalist upon the effects of extraordinary 

 seasons in the distribution of animals and plants. Speaking 

 of the winter of 1871-72, he remarks that it was one of the 

 driest on record in New England, the rain-fall not only being 

 much less than usual, but also coming in such a fashion as to 

 leave the ground very dry during the winter. The snow-fall 

 was slight, and did* not lie well upon the ground, so that great 

 portions of the surface were quite unprotected. Under these 

 circumstances the long-continued and steady cold froze the 

 earth to a great depth, the freezing extending as much as five 

 feet below the surface in some places, and being suflScient 

 throughout the whole of New England to involve the roots 

 of the ve2:etation and the forests. The effects observed were 

 in all probability due not only to the intensity of the cold, 

 but to a presumed deficiency of sap in the plants in connec- 

 tion with the low temperature ; the roots remaining for some 

 time in contact with relativel}'' dry earth, as the frosts left 

 them, causing a shock too great for their vitality to withstand. 



The tree which suffered most was the arbor-vitae {Thvja 

 occidentalis) , more than half of these having died, and the 

 rest being in a critical condition. The red cedar was likewise 

 a great sufferer, as also the yellow and white jDines ; indeed, 

 all the coniferae in New England have been injured to a greater 

 or less degree. The greatest damage was experienced in 

 sandy soils. 



The only change in animal life noticed by Professor Shaler 

 is the comparative scarcity of snakes, which he considers to 

 be a very decided feature. An interesting point in this con- 

 nection is the question as to what would have been the effect 

 of carrying the action of the climate a little farther; since, 

 small as the destruction of forest trees is, it will doubtless 



