188 Agricultural Experiment Station, Ithaca, N. Y. 



Outline of the Nutrition of Plants. 



(Given at the Jamestown School.) 



(By E. J. Durand.) 



All plants hiiilt up of cells. — Various forms of cells in different 

 parts of the plant. 



The green coloring matter of plants {chlorophyll). 



The essential elements of plant food. — These are obtained (1) 

 from the soil, (2) from the air. The food of the seedling; of the 

 mature plant. 



What is sap f — Water and certain soluble portions of plant food 

 are absorbed from the soil by the root hairs. Forced up through 

 the sap-wood or inner bark by root pressure. Most of the water is 

 evaporated from the leaves through the stomates. The constant 

 current of water from the roots to the leaves. Some of the water 

 combined with the carbon dioxide of the air forms starch. 



Assimilation. — This process can take place only in the presence 

 of chlorophyll and light. Parasitic plants containing no chlorephyll 

 cannot assimilate carbon dioxide. 



The diffusion of the assimilated food. — It may be used at once ; 

 or stored up, usually (1) roots, e. g.., carrot, maple, or (2) underground 

 stems, e. g. potato — This stored up material forms the food of many 

 plants in spring before the leaves start. 



Respiration., the breaking down of tissue and its burning up with 



oxygen. 



Pollen : What it is, and what it does. 



(Given at the second Fredonia School.) 



(By E. J. Durand.) 



1. Stamens and Pistils. — The essential part of a flower ; their 



sexual function. 

 Pollen. — The floury mass of nn'nute grains borne in the anther, 

 the sack at the upper end of the stamen. 



2. The poUen-grain consists of a rounded bit of ^md, protoplasm^ 



surrounded by two membranes. Some of the forms of pol- 

 len. After being scattered by the anther, the pollen is 

 carried by the wind or by insects, or other agencies, to the 

 pistils of other plants of the same species. 



