CYCAS CIECINALIS. 71 



from 4 to 10. Af^ tliese groups were finally separated from the bombs they were 

 discharged with considerable velocity into the andnent liquid, the bomb itself suf- 

 fering a corresponding recoil. * * * The field of vision in the vicinity of the 

 bomb became partially covered witli these long crystals, but the supply within the 

 boml) did not seem to diminish materially. There must have been hundreds of 

 the arrows in one single spheroid. * * * If the plant is not thoroughly cooked 

 its acrid qualities remain in some degree. If thoroughly cooked they are destroyed. 

 It is interesting to note that in cases where the leaves are chewed, either fresh or 

 dried, the stinging sensation is not perceived until a few moments afterward, and in 

 many cases it is not until the taro has been eaten that the prickly sensation in the 

 lining of the mouth and throat shows that it has not been thoroughly cooked. * * * 

 Alocasia indica, a plant closely allied to the taro plant, is so acrid that the Pacific 

 Islanders resort to it only in cases of great scarcity of food. The disagreeable effects 

 caused by these jilants seem to be confined to the tem})orary prii'kling sensation of 

 the mouth and throat. They are undoubtedly uutritioas and are held in high esteem 

 by the natives. 



The role played In^ raphide.s in protecting plants from herbivorous 

 animals has been discussed by Otto Kuntze, in the Heft zur Botanis- 

 chen Zeitung-, 187T, and by Ernst Stahl in the Jenaische Zeitscrif t f iir 

 Naturwissenshaft und Medicine, 1888. The phenomenon of the explo- 

 sion or shooting forth of the needles was lirst noticed by Turpin in 

 1836. He called the capsules containing them ''biforines," errone- 

 ously supposing them to be proyided with an opening at each end. 



CYCAS CIRCIXALIS AND ITS FECCXDATIOX. 



One of the most interesting plants growling in Guam is the "fadau,"' 

 or "federiko'"' {Cycas circinalis)^ the nuts of which were a food 

 staple of the aborigines before the discoyery of the island. Its cylin- 

 drical, scarred trunk, and stiti*, pinnated, gloss}" leaves suggest ideal 

 pictures of the forests of the Carboniferous age. (PI. VHI.) Its 

 nuts, poisonous when crude, but abounding in starch, are converted 

 into a nutritious arrowroot, or sago, in several tropical countries. 

 But its chief interest is in the structure of its inflorescence and the 

 manner of its fructification. The group of plants to which it belongs 

 occupies a place intermediate between the flowering plants and the 

 cr3q)togams. Like the former, it has fruit with a large starchy endo- 

 carp, but, as in the latter, fecundation is accomplished by means of 

 spermatozoids and archegonia, corresponding to the male and female 

 elements in animals. The male inflorescence is in the form of an 

 erect cone consisting of modified staminal leaves which bear on the 

 under surface globose pollen sacs corresponding to microsporangia. 

 The female inflorescence consists of a tuft of spreading carpellary leaves 

 having their margins coarsel}' notched. (PI. XIV.) In the notches 

 are situated the ovules, which are devoid of an}^ protective covering. 

 The}^ correspond to macrosporangia. Pollination is effected l)y the 

 wind. The pollen settles on the ovules and sends down a tube into 

 the tissue of the nucellus. Archegonia are formed, Qgg cells develop, 



