84 PLANT PHYSIOLOGY. 



CORRELATED TOPICS. 

 Theories as to the fundamental significance of the copiousness 



of transpiration. 

 Ecological aspects of Transpiration and its relation to plant 



form and position. 

 Causes of wilting; relation of checking of transpiration to 



restoration of turgidity. 

 Ice-formation on plants. 

 Hydathodes. 

 Summary of the various offices of water in the Plant. 



LITERATURE. 



Brown, H. T. Vice-Presidential address in Nature, 60, 474. 

 Stahl's and other important works should be traced through 

 Pfeffer. 



D. Metabolism, (a] Photosynthesis. 



You have learned from studies in earlier courses that plants 

 make starch in their green parts in the presence of light, a 

 process called Photosynthesis. We have now to examine this 

 process in some detail. 



49. What is the physical and chemical composition of the 

 usual end-product of Photosynthesis, i.e., Starch? 



Answer as to chemistry from your various sources of infor- 

 mation ; as to physical composition, by an observational and 

 polariscopic examination of starch grains from the potato 

 (scraped from a cut surface, and mounted in water). 



Apply and observe the effect of the iodine test (described 

 in 51). 



50. What structures are concerned in Photosynthesis? 

 Answer by diagrams showing: 



(a) Quantitatively and qualitatively the distribution of 

 Chlorophyll in a complete higher plant, and 



(//) The structure of the most specialized green chlorophyll- 

 bearing organ, and 



(c] The structure of a single green cell. 



