1 68 The Ohio Naturalist. [Vol. IV, No. 8, 



completed under Prof. John H. Schaffner in the Botanical Labor- 

 ator}^ of Ohio State Universit}^ to both of whom I wish to 

 express my sincere thanks. 



In Nelumbo, the carpels are situated in deep pits of the top- 

 shaped receptacle. The stigma and the narrow canal which 

 traverses the short style are covered with glandular cells which 

 secrete a mucilagenous fluid at the time of pollination (Fig. 8). 

 The ovule is suspended from the summit of the ovulary (Fig. i). 

 Some time before the integuments begin to develop, the growth 

 of the ovule is more rapid at one side ( Fig. r ) and anatrophy is 

 well marked when the incipient seed-coats make their appearance. 

 A single hypodermal archesporial cell can be easily distinguished 

 from the adjacent cells by its larger size and more granular cell 

 contents (Fig. 2). Very earl}- in its development, it divides by 

 a transverse wall into an upper cell, the primary parietal cell and 

 a lower cell, the megasporocyte (Fig. 3). By a series of divisions 

 of the primary parietal cell, a large parietal tissue of twelve 

 cells, arranged in three tiers of four cells each, is formed (Fig. 5). 



The megasporocyte expands almost equally in all directions. 

 The divisions of the megasporocyte were not followed, but four 

 megaspores are formed. The lowest one becomes the functional 

 megaspore while the others degenerate (Fig. 6). By the further 

 division of the parietal tissue and the epidermis at the tip of the 

 nucellus, the functional megaspore becomes deeply placed in the 

 ovule (Fig. 7.) The nucleus of the functional megaspore now 

 divides into two (Fig. 9), four (Fig. 10), and eight nuclei 

 respectively, producing the eight-celled embryo-sac (Fig. 11). 

 Frequently great irregularities in the development of the embryo- 

 sac were present. In many cases two or more imperfect sacs were 

 observed. Usually there was one complete sac with one or more 

 imperfectly developed sacs. By the appearance of the prepara- 

 tions, it seems that the extra sacs are derived from sister mega- 

 spores, rather than from independent megasporocytes (Fig. 15.) 



The embryo-sac developes very rapidly and is usuall}^ straight. 

 It enlarges principally in the direction of its longer axis, destroy- 

 ing the parietal cells above and encroaching on the ovular tissue 

 below. The antipodals are small (Fig. 11) and usually disappear 

 before the conjugation of the polar nuclei. In only a few instan- 

 ces could any trace of them be found after the polar nuclei had 

 conjugated. The synergids are small. They become slightly 

 enlarged from their original condition, and are elongated trans- 

 versely to the longer axis of the sac. They degenerate about the 

 time of fertilization or .soon after (Fig. 12). The egg becomes 

 quite large and usually is placed considerably to one side of the 

 sac (Fig. 13). 



The polar nuclei begin to conjugate about the time the flower 

 opens and the fusion is not complete until after fertilization. In 



