AXIS FLOWERS 305 
strongly 2- lipped, and its attached stamens are reduced 
to two, the other three having disappeared. The 
bicarpellary pistil contains two ovules 
in each carpel cavity. The calyx is 
gamosepalous. 
In the Salvia and the related mints ( aa . 
we have the highest development of (a) 
the Axis Flowers. Compare them with 7 
the Buttercups and Magnolias, and  yyg. 180salvia. 
note what changes have taken place. 
The axis has been shortened and reduced; the carpels 
have been reduced from many and separate to two, 
united; the stamens, from very many to two; the petals 
from separate (apopetalous) to united (gamopetalous) ; 
as well as from regular to irregular; the sepals, from 
separate to united. 
Laboratory Studies. (a) Examine externally and by cross 
and longitudinal sections the seeds of Castor Bean (Ricinus), 
Pea (Pisum), and Squash (Cucurbita), noting the character of 
the seed coat; the presence of endosperm in Ricinus, its absence 
in the other two; and the two cotyledons, and between them the 
rudiments of the next leaves (the plumule). Where the endo- 
sperm is lacking note that the cotyledons are thickened into 
storage organs. 
(b). Germinate some of the foregoing seeds, examining at 
frequent intervals, and note that in the Castor Bean the thin 
cotyledons remain in the seeds (in contact with the endosperm) 
for a longer time than in the Squash, but eventually in both they 
become green, and function as leaves. In the pea the hemi- 
spherical cotyledons are too thick to function as leaves, and 
remain in the seed coats. 
(c) Examine, in sections if necessary, a flower of the common 
Mallow (Malva), or of Hollyhock (Althaea), or Cotton (Gossy- 
pium), noting number and arrangement on the torus of the 
united carpels, united stamens, petals and sepals, bearing in 
mind the resemblance to and differences from the general plan 
of the Buttercup type of flower. 
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