SUMMER MEETING. 49 



When death is caused by low temperature, in many respects, the results are 

 similar to those produced by too great an elevation. There is observed the 

 same coagulation of the albuminoids, resulting in the destruction of the power 

 of the protoplasm to imbibe water, and, as a consequence, in the loss of the 

 turgidity of the cells. Moreover, as in the case of injury from high tempera- 

 ture, those cells which are the most watery are the ones which, other things 

 being equal, are injured most quickly by a reduction of temperature. Embryo 

 plants in seeds, when dry, are able to endure almost any degree of low temper- 

 ature; but after they have germinated, and the cells have become watery, they 

 are generally killed by a reduction to, or a few degrees below, 33° Fahr. So, 

 too, the comparatively dry tissues of the winter buds and ripened stems of the 

 native trees and shrubs in cold countries are rarely injured, even in the severest 

 winters, while the young leaves and shoots in the spring are often killed by 

 slight frosts. 



Death from low temperature is always accompanied by the formation of ice 

 crystals in the succulent tissues. Much of the water thus frozen is that which 

 tills the vacuoles of the cells, while some of it is that which moistens the pro- 

 toplasm and cell walls. 



Now, it is evident that the water in the large vacuoles is much more easily 

 congealed than that in the protoplasm and cell walls; for, in the latter, the 

 force of adhesion between the molecules of protoplasm or cellulose and the 

 imbibed water offers a considerable resistance to the separation of the water in 

 ice crystals, and this resistance is greater as the contained water is less. As 

 the liquid in the vacuoles is not pure water, but a mixture of several solutions, 

 it freezes at a lower temperature than water, and then, according to a well- 

 known law of physics, separates into pure ice crystals and a denser unfrozen 

 solution. 



A plant which has been frozen may survive, in many instances, if thawed 

 slowly, whereas, if thawed quickly its vitality is generally destroyed. 



Dr. Beal: This closes the exercises to be presented by the members of the 

 sophomore class. 



After the answering of a number of questions propounded by members pres- 

 ent the Society adjourned until Wednesday morning. 



Wednesday — Morning Session. 



Vice-President Gibson called the meeting to order on time, and although the 

 attendance was light the discussion of 



STRAWBERRIES 



was resumed by the Secretary reading the following note from R. D. Graham, 

 of Grand Rapids, on 



VARIETIES TO SUIT DIFFERENT MARKETS. 



So far as my observations extend, the difference in markets is not very great, 



7 



