60 PLANT PHYSIOLOGY. 



must permit the primary functions of the Protoplasm to go on, 

 and allow for the several secondary needs of the organism. 

 How is such a skeleton built ? 



14. What primary principle determines in multicellular plants 

 the general size of the Cell ? 



How do protoplasmic masses act when they grow to the limit of 

 the normal cell-size ? 



Answer from earlier studies or other sources of information. 



15. How are the different Protoplasts of one organism kept in 

 physiological continuity ? 



Answer from a review of your knowledge of continuity of 

 Protoplasm, and from your other sources of information. 



16. What are the main principles upon which a multicellular 

 mass of Protoplasm builds its skeleton (in Plants) ? 



This subject is supposed to have been covered by your 

 earlier studies in anatomy, and should need simply review 

 from the physiological point of view. It should be worked out 

 here in synoptical paragraphs, illustrated by diagrammatic 

 drawings. Following are the most important topics : 



a. What is the difference in the principle of skeleton-building 

 in the higher plants as compared with the higher animals? 



b. How is the cell-wall substance built by the Protoplasm ? 



c. What is the physical and chemical composition of cell-walls ? 



d. What shapes, thicknesses, and sizes may cell-walls assume? 



e. How do tissues and organs arise ? 



17. Write, in your Laboratory books, a synoptical essay 

 upon THE STRUCTURE AND PROPERTIES OF PROTOPLASM. 

 It is to consist of a logically arranged and properly propor- 

 tioned synopsis of the subject deduced from all of your sources 

 of information. It should be prefaced by a tabular outline of 

 contents and should not exceed six hundred words in length. 



o 



LITERATURE. 



The standard work on this subject is Haberlandt's " Phy- 

 siologische Pflanzenanatomie. ' But the general works, espe- 

 cially Strasburger's "Text-book,' 1 contain sections upon it. 



