Development of Cassytha filiformis, L. 407 



hand, appeared above ground without any seed coat (Fig. 

 4, c). 



From the fact that the seed coat borne on the top of the 

 seedHng is always quite empty, and from the size and con- 

 tents of the hypocotyl, as well as the embryonic appearance 

 of the seedling, it seems highly probable that in the begin- 

 ning of germination, and as soon as the hypocotyl is fairly 

 out of the seed, all the cotyledonary food is passed into this 

 lower portion previous to its being actually needed, and then 

 the cotyledonary connection is broken. The scar of this 

 separation is carried far up the stem by rapid and extensive 

 elongation of the thin green portion. One seedling extracted 

 itself from the seed when small and then continued growing, 

 but the shell hung to the side of the seedling. Here con- 

 nection had not been broken, although the seed was empty. 

 The cotyledons were present as two papery flakes. 



4. Relation of the Seedling to the Mature Plant. — The 

 plumule usually bears two leaves of the characteristic small 

 size. Owing to the great attenuation of both the hypocotyl 

 and epicotyl, there is considerable space between the ground 

 and the first leaf. In the case of the seedling that had been 

 caught as above described, the distance was six inches. 

 Haustoria may, however, form below the first leaves, as the 

 bundle system is fully formed. 



The seedling, as soon as it begins to grow erect, shows 

 active circumnutating movements in clockwise direction. 

 The sweep comes from a considerable distance dow^n the 

 stem and is fairly rapid. The seedling that was described 

 as having been held wdthin the seed wall and grown there 

 to a length of nearly an inch, when freed, uncoiled com- 

 pletely and was beginning to circumnutate after ten minutes. 



5. Histology of Seedling Plant. — The hypocotyl has a 

 delicate epidermis with stomata, but very little cuticle. The 

 fundamental tissue consists of loose, empty-looking cells, 

 which are, however, quite turgid with sap and very rich in 

 sugar. There are four patches of protoxylem evenly dis- 



