232 Salisbury . — The Extra-floral Nectaries of the 
filled with a dense granular and highly refractive cytoplasm and possess 
large nuclei. At maturity they become markedly vacuolate. This vacuo- 
lation was observed by Gardiner (7) in the gland cells of Dionaea , and more 
recently, Miss Huie has shown that the gland cells of Drosera exhibit 
vacuolation, which is most marked at the period of secretion (9). See also 
Saunders (13). 
The development of the nectaries was studied in P. cuspidatum , and 
agrees with that described by Schwendt (15, p. 250 ) for Muehlenbeckia 
sagittifolia. 
Fig. 3. Development of nectai'y glands in Polygonum cuspidatum , shown in vertical section. 
The successive stages are seen in a, b, c, d. In e , the longitudinal division of the glandular portion 
has taken place before the completion of the last horizontal division. The figures 1-4 denote 
successive stages in development. x 460. 
The development of the trichomes starts from the centre of the nectary 
and passes to the periphery. It begins with the radial division of the 
gland mother-cells in two planes at right angles to one another. Division 
parallel to the surface of the nectary then takes place, and we thus have 
formed an upper and a lower story, each of four cells. The cells of the 
upper group again divide horizontally, and we thus have formed the three 
series representing the basal, stalk, and gland cells. This sequence may, 
however, be subject to slight variation (Text-fig. 3 , e ). 
