510 NEW JERSEY AGKICCLTUKAL COLLEGE 



Tn another ex])eriment a ])ortion of the seed-coat was removed from 

 one side of each of five .-quash seeds. The mutilated seeds were 

 planted in pots February 6th, and at tlie same time five untreated 

 squash seeds were planted in like manner; all of the mutilated seeds 

 failed to trerminate. 



Seedlings of Martynias or Unicorn-Plant. 



In connection with the crossing of martynias a study was made of 

 the seeds and seedlings. The seeds themselves are very irregular in 

 shape, due to being packed closely in the narrow cavities of the horn- 

 like capsule, and, while nearly black, glisten at certain ])laces upon their 

 warty surface. The seeds are very slow and irregular in germination,, 

 and new seedlings will continue to appear in a seed-box for weeks 

 and even months after the first have come to the surface. 



One of the points of sjjecial interest in this connection is the pres- 

 ence of the heel or peg as has been mentioned for the squashes and 

 allied plants. The peg has the same position upon the hypoctyl as- 

 in the squashes, and evidently performs the same function, namely^ 

 the removal of the hard, thick seed-coats from the cotyledons that 

 would otherwise interfere with tlie development of the seedlings. 

 A series of seedlings of the Martynia Louisiana Will, is shown in 

 Plate XL (middle third), giving the various stages of growth from 

 a seed, with the root tips only extending beyond the hard, dark, rough 

 seed-coat to 'a plant with the first pair of true leaves widespread. A 

 study of these photographic reproductions will indicate rthe part the 

 conspicuous peg plays in the germination of this plant. Purposely 

 the empt}^ seed-coats have been removed from some of the seedlings 

 that the peg may be the better seen. In the three plants at the rights 

 for example, the position of the empty seed-coats, as held l)y the peg» 

 is quite naturally represented. 



This provision for the removal of the hard, thick seed-coats from 

 the martynia plantlets has been noted by Xobbe* with figure, and by 

 Darwin in his book previously quoted. It only needs to be added that 

 the importance of the peg is abundantly shown by any seedling that 

 from any of several reasons has not been fortunate enough to leave 

 the seed-coats attached to the peg. liut instead bear tliem aloft upon 

 the cotyledons, which are thereby prevented from expanding or the 

 plumule from taking on its natural development. 



*Handbuch der Samenkunde, 1876, page 215. 



