CANNABIS SATIVA 113 



around the carpel until it encloses approximately two-thirds of 

 it. (Fig. 106, D-H.^ This becomes the membranous perianth 

 described above. Briosi and Tognini observed knob-like projec- 

 tions at the base of the ovary and above the perianth, and inter- 

 preted them as being rudimentary primordia of stamens that become 

 arrested in development. (Figs. 105, D, and 106, M.) 



Zinger's (31) account of the ontogeny of the carpellate flower is 

 at variance with the above in respect to the development and 

 character of the perianth. In most of the varieties of hemp which 

 he examined, there were two distinct perianth primordia. The 

 first primordium appears at the base of the floral axis on the side 

 toward the floral bract, while the second develops on the dorsal 

 side of the floral axis at a higher level than the first. Both may 

 appear somewhat late in ontogeny, so that they are not perceptible 

 until the carpellary primordia are differentiated. In most in- 

 stances, the primordium on the side toward the floral bract persists 

 as a small protuberance without further development; and this is 

 sometimes the case with the posterior primordium, so that there 

 may be no perianth when the fruit is mature. When the posterior 

 primordium develops, it forms a thin, round or elliptical scale-like 

 structure which lies on the dorsal side of the ovary. Zinger found 

 a perianth completely enclosing the basal portion of the ovary in 

 two horticultural varieties which he designated as Cannabis 

 gigantea Hort. and C. himalayana Hort. 



At the base of the nucellus, the inner and outer integuments 

 arise in that order, the inner one at first exceeding the outer in rate 

 of growth, but ultimately being overgrown and enclosed by it. 

 (Fig. 106, K, L, M.) As noted by Zinger, the massive inner integu- 

 ment becomes completely coalescent with the thick outer one, and 

 covers the apex of the nucellus in such a way that the micropylar 

 canal becomes entirely closed by the integumentary tissue. Fol- 

 lowing pollination, the pollen tube either grows through the tissue 

 which fills the micropyle or pierces the two integuments; and, 

 upon reaching the nucellus, it branches about its apex, finally 

 sending a single branch into the megagametophyte. 



Embryogeny. — Following fertilization, the transverse seg- 

 mentation of the zygote produces the suspensor and embryo proper. 

 The suspensor never becomes elongate, remaining as a short stalk 

 of one or two cells. (Fig. 106, 0.) The embryo is at first globular 

 but there is an early differentiation of the cotyledons which develop 



