TRANSACTIONS OF NORTHKRN ILL. HORTICULTIRAL SOl lETV. 2.>1 



FIRST DAY. 



EVENING SESSION. 



The Society convened, as per adjournment, with the President in the 

 chair. 



The discussion was resumed, during which 



Mr. Budd stated that Prof. Mohr, of Germany, had been investiga- 

 ting tissues of plants and insects, and found that the particles of water in 

 the cells may be so minute — so finely divided — that they will not freeze ; 

 and that where they are not so finely divided as to escape frost, the roots 

 will perish or the plant or insect will die. 



He said that on examining damaged trees we find the bark and the 

 cells immediately under the bark healthy, while farther inward the cells 

 are ruptured and the tissue diseased ; which shows that the former were, 

 and the latter were not, in proper condition to enter the winter. 



Mr. McAfee said that hardiness depends upon cell stnicture, and 

 that damage by cold depends upon the motion of the air, quite as much 

 as the degree of cold ; as in a period of cold of definite duration the 

 damage is not as great if the air is calm, as in another period of same 

 temperature and duration accompanied with a strong northwest wind ; 

 for it is well known that a northwest wind is '' a very drying wind," as it 

 is called ; and evaporation takes place rapidly under it. He claimed that 

 barometric pressure, also, has much to do with the drying of vegetation, 

 and consequent damage by extreme frost. 



He explained the circulation of sap through cells instead of by capil- 

 lary attraction, as formerly taught ; 'said the theory of the formation of 

 albumen at the extremities of medullary rays has been proved a fallacy, 

 for he had known instances in which the bark had been started off the 

 trunks of trees so that there was n(j direct connection between bark and 

 wood, and yet the growth continued on the inner bark. ;ind woody fiber 

 was ultimately formed there. 



He said the action of frost in winter, upon the sap of the Sugar Maple 

 and other sugar producing trees, seemed to have the efiect of changing 

 starch into sugar. 



Mr. Budd said the vigor or hardiness of varieties of trees depends 

 largely upon the leaves; if these are healthy and perform their functions 

 well through the season, there is seUlom damage to tree or vine by the 

 winter. He instanced the Tetofsky api)Ie leaf as always perfect, hence 

 this tree was never known to be injured by the winter. New varieties of 

 grapes, whose leaves did not retain their color and i)erfc)rm tlieir functions 

 through a drought, could not be dei:)ende(l upon as liardy. 



