Growth. 2 7 



the results will be more valuable. Examine the data accu- 

 mulated in observations extending over a week, and ascer- 

 tain time of the day or night in which the greatest growth takes 

 place, and also period in the development of the fruit when 

 it increases most rapidly. 



Mark off intervals on a line drawn longitudinally from the 

 base of the fruit, and note the increase in size in the same 

 manner in «'hich stems were studied. 



17. Growth of a cell — Take a bit of epidermis from 

 young buds of any member of the squash family, or from 

 unopened flower buds of wandering jew [Tradesca/itia), mount 

 in rain water, and examine with the microscope. Make a 

 drawing showing form, size, and disposition of the nucleus, 

 wall, and protoplasm. This may be done best after a drop of 

 iodine solution has been run in under the cover glass. Mount 

 some epidermis from an opened bud, and make similar drawing 

 of the cell. What changes occur in the cell during its growth 

 and development ? 



18. Awakening growth. — A great number of peren- 

 nial plants form tubers, or thickened stems, or shoots of some 

 kind, in which condition they endure unfavorable seasons, and 

 the development of a seed or spore is usually followed by a 

 resting stage, in which the plant may remain for a long time 

 under the most adverse conditions. The growth of a plant 

 from these forms is of great interest, since, in the case of all 

 seeds and some tubers, corms, and also some cuttings, it is 

 accompanied by the phenomena of development of an adult 

 form from an embryonic or juvenile form. 



19. Awakening growth of a tuber. — Place a number 

 of potatoes in moist soil, in a warm room, in midwinter or early 

 spring. A few days later note the growth of buds on the upper, 

 or apical, portion of the potato. A thickened stem of limited 

 growth is formed from every bud, or " eye." Cut away 

 those formed first, and note that their destruction is fol- 



