330 BOTANICAL GAZETTE [November 



made up of nucellar tissue, or perisperm, richly stored with starch 

 {fig. 32), the grains of starch in the outer cells being finer and 

 less abundant than in the inner ones. 



Near the upper end of this perisperm mass, separated from 

 the integument by but two or three layers of cells, lies the some- 

 what oblately spheroidal mass of endosperm [fig- 3 2) . This mass 

 is O-Oq"""^ to 0.1"'"' in diameter, and is made up of forty or more 

 cubical cells with darkly staining contents, including abundant 



aleurone grains (Johnson, igoo^, fig. 13). 



The embryo is rounded or slightly elongated, without a well- 

 marked suspensor or other sign of differentiation, and lies at the 

 upper border of the endosperm {fig. 32), It is surrounded lat- 

 erally and below by one or two layers of endosperm. It is 0.03 5"^"* 

 to 0.04"'"' long, and is made up of about fifteen cells. 



In many sections of the ripe seed a group of cells, correspond- 

 ing in position to a sjmergid, is found near the upper end of the 

 embryo, and seems entirely distinct from the endosperm (John- 

 son, 1900^, p. 6). Observations made thus far fail to show anything 

 peculiar in the fate of this group of cells during germination. 

 These cells and the six other peripheral cells outside the endo- 

 sperm (Johnson, 1900% fig. 13) are soon crushed aside by the 

 swelling of the latter in sprouting. 



Seeds of Peperomia pelhicida collected in Jamaica in August 

 1900 germinated readily in October of that year. They there- 

 fore do not need this long rest apparently necessary for the 

 seeds of Sauninis cermius (Johnson, 1900^, p. 369)- The 

 exact course of development, that is the time of ripening and the 

 length of rest required by the seed under the normal conditions, 

 must of course be followed out in the tropics. In Baltimore the 

 behavior of the seeds is as described below, when allowed to 

 germinate on wet filter paper or chopped Sphagnum, at a tem- 

 perature of is"" to 20°, before an unshaded window, but not in 

 direct sunlight. 



No external change whatever is visible in the seed for about 

 a week, except an immediate slight swelling of the carpellary 

 tissue, but important changes are going on within. The embryo 

 grows to o.i"'"'in diameter, remaining globular in shape, and is 



Mi 



