276 PHYLUM XII. CYCADOPHYTA 
Laboratory Studies. (a) In many greenhouses may be 
found well-grown specimens of Cycas and Zamia. Examine 
these for the general appearance of Cycads. 
(b) On inquiry it is possible that microspore cones of these 
common Cycads may be found, and secured for a closer study. 
(c) Old trees of Cycas produce their ‘‘flowers” of mega- 
sporophylls every few years, and on inquiry some of the latter 
may be secured in various stages of development for dissection 
and study. 
(d) Zamia plants in greenhouses frequently produce their 
thick, rounded megasporophyll cones. These should be dis- 
sected to find the sporangia (seeds). 
(e) It should be remembered that various Cycads, including 
Cycas and Zamia, grow in the Gulf states, and specimens may be 
obtained for study without much difficulty. 
(f) Ginkgo trees are grown in many parks and door yards, 
and may be examined for their foliage and general appearance. 
(g) In the spring look for microsporophylls and megasporo- 
phylls of Ginkgo and later for ripe, fleshy seeds. 
(h) From the middle of June to early in July, depending 
upon the location, the sperms can sometimes be observed in the 
seeds as follows: Take a seed and with a stout knife split off 
two opposite sides (including the stony part of the integument). 
If properly made a slice will be removed from each side of the 
megagametophyte which can be removed with a portion of 
the megasporangium (nucellus) adhering as a cap to its apex. 
Upon carefully lifting this cap the microgametophytes will be 
found hanging to its under side as thick, glistening, tube-like 
bodies. Carefully dissect these off with very sharp scalpel 
and mount in a solution containing about 5 per cent. of cane 
sugar. The sperms (or at least the cells from which they arise) 
will readily be visible even under low power of the microscope, 
as they are very large, attaining a diameter of 0.1 millimeter. 
LITERATURE OF CYCADOPHYTA 
J. M. Courrer and C. J. CHamperiain, Morphology of 
Gymnosperms, Chicago, 1910. 
M. C. Stops, Ancient Plants, London, 1910. 
