PAPERS ON BIOLOGY AND AGRICULTURE 91 



SEEDLING VASCULAR ANATOMY OF NELUMBO 



LUTEA 



Isabel S. Smith, Illinois College, Jacksonville 



This investigation was begun in 1913 in the hope of 

 throwing further light on the origin of the monocotyls 

 and dicotyls. During the progress of the work the de- 

 velopment of the megasporangium, the megaspore, the 

 female gametophyte (embryo sac), the proembryo and 

 the embryo has been retraced. My preparations seem 

 to be in agreement with the work of Lyon (6), York (7), 

 Cook (2), and Conard (1). The only addition that I 

 make to what is already known is the seedling vascular 

 anatomy. 



Material was obtained from the Illinois River at Mere- 

 dosia, Illinois; from the Huron River at Huron, Ohio; 

 from Grass Lake, Wisconsin ; and from seedlings grown 

 in the greenhouse of the Botany Department of the Uni- 

 versity of Chicago. 



Seedlings which had "germinated" naturally in the 

 Illinois River were collected at Meredosia, June 3, 1913 

 (Fig. 1). As there was a severe flood that year germina- 

 tion must have been unusually late. The seedlings were 

 in some cases still in the top-shaped flower receptacles, 

 but had developed so far as to have rhizomes and ad- 

 ventitious roots. Some freed seedlings were found. 

 These showed how evanescent is the primary root; for 

 it had never grown beyond the cotyledons. Adventi- 

 tious roots had developed. 



The development of megaspores and microspores, pol- 

 lination, fertilization, the development of the embryo and 

 seed formation, must proceed very rapidly ; for all these 

 stages were obtained from flowers and fruits collected on 

 a single day, August 25, 1914, at the mouth of the Huron 

 River. The seeds of course were not mature, the coty- 

 ledons were green and the seed coat had not been formed ; 

 but they were normal in size. In the fall the receptacles 

 drop to the bottom of the stream, lie dormant during the 

 winter, and the seeds "germinate" probably the suc- 

 ceeding spring. 



