Development of Cassytha filiformis, L. 401 



At times it runs along the white sandy ground a distance 

 of eight or ten feet, becoming of a tawny yellow color, till 

 it again reaches some host plant. 



The plant will be treated of as follows : 



1. Fruit and seed structure. 



2. Seed germination. 



3. Seedling growth. 



4. Relation of the seedling to the mature plant. 



5. Histology of seedling plant. 



6. Histology of mature plant. 



/. Fruit and Seed Structure. — Of the spike of four to 

 eight flowers the lower ones mature first, and there seem 

 to be considerable differences between the members of a 

 single spike in time of flowering, as the lower fruits are 

 sometimes fairly well on to maturity, while the upper buds 

 are not yet open. 



The fruit is of a clear, watery white color, generally 

 spheroidal, and six to seven mm. in diameter when fresh. 

 It dries to a brownish black color, the succulent pulp of the 

 pericarp shrinking to a leathery consistence and somewhat 

 reducing its size. The remains of the perianth segments 

 are quite evident as little papery teeth at the "blossom end," 

 directly opposite the point of attachment to the stem. Here 

 the remains of the tubular calyx and the stigma sometimes 

 also persist, the fleshy receptacle forming a pericarp or 

 pseudocarp, which is attached to the fruit proper only at 

 the base. The fruit is sessile, like the flower. 



Fig. I (Plate xxxiii) represents the fruit in longitudinal 

 section, and Fig. 2 a section of its walls in detail. 



The receptacular tube consists of a rather tough epidermis 

 of a single layer of cells without intercellular spaces, but 

 with a few stomata ( Figs, i and 2,1); beneath which lie 

 several irregular layers of loose, rounded cells rich in gran- 

 ular material (2), giving succulence to the fruit. Toward 

 the interior these cells flatten somewhat and give place to 

 large, irregular spaces (3), which in the younger stages 



