8 STUDIES OF SEEDS AXD SEEDLIXGS 



Carefully remove for study the structures iliscovereJ witliiu. Exam- 

 ine them with the lens. Describe all parts of the kernel with included 

 embryo. 



The substance surrounding the embryo is the nllninicn : the leaves 

 are the coli/leilum: : the axis, or stenilet upon which they are borne, is 

 the cdiilicU'. 



Draw : (1) The embryo separated from the albumen ( x ■2).^ (2) A 

 longitudinal section of the kertiel cutting the cotyledons in halves ( x ^l). 



White Lupine. — The parts all become visible on remciving the seed 

 coats and separating the well-tuarked halves of the seed. Note caulicle, 

 cotyledons, and between the latter a tliird part, the plunnile. of several 

 diniiuutive members. Compare with the embryo of Castor Bean, 

 noting striking differences. 



Draw the embryo with one cotyledon remored, so as to show the 

 plumule ( X '■)). 



Indian Corn. --Lying just beneath the surface of the grain is a 

 roughly wedge-shaped boily. liemove this, leaving the pasty portion 

 — the albumen. In one face is a cleft. I'uU this apart, exposing 

 structures within. 



Stiulv the embryo now in hand. A longitudinal section will help. 

 In ordei' to identify more surely the members of the embrj'o, study 

 a!so a sprouted seed, in which root and plumule show plainly. The 

 large single cotyledon is one feature to lie especially noted. 



Compare and correlate all its different portions with the parts of 

 the embryos of Castor l>ean and Lupine. 



Draw surface and sectional views of the emliryo to show the 

 structure ( x :j). 



From the examples above answer the question, To what extent 

 is the new plant already formed within the seed before germination 

 begins? 



Exercise IL The Provision' or Food Designed for the 

 Earliest (trowth of the Young Pl.^nt 



1. Where is the nourishment stored ? Answer this for Castor Bean, 

 Lupine, and Indian Corn. In addition, examine seeds of the Four- 

 o'clock, and others provideil by the teacher. 



Longitudinal sections will generally show at once the location of the 

 food store, whether outside the embryo, in which case the seed is said to 

 be alhuiiiinous, or within the much swollen tissues of the luiscent plant 

 itself, when the seed is called exalhumiiious, or lacking in albumen. 



Classify the seeds studied as albuminous or exalbnniinous. 



1 Tliis means the drawing is to he two times the size of nature. 



