46 a PHA NER OGA MS. 



nearly a foot in height, rising above the insertion of the two enormous leaves 

 on the periphery of the broad apex of the stem. The branches of the inflor- 

 escence are terete and jointed, spring from the axils of the bracts, and bear 

 upright longish cylindrical cones ; these are furnished with from seventy to ninety 

 broadly ovate scale-leaves standing closely one above another in four rows, a 

 single flower being seated in each axil, male and female in different cones. The 

 male flowers are pseudo-hermaphrodite, and possess a perianth consisting of 

 two pairs of decussate leaves; the lower ones are entirely free, sickle-shaped and 

 pointed, the upper ones broadly spathulate and coherent at their base into a com- 

 pressed tube. Within this tube are six stamens monadelphous at the base, with 

 cylindrical filaments and terminal spherical bilocular anthers, which dehisce above 

 the apex with a three-armed fissure; the pollen-grains are simple (?) and elliptic. 

 The centre of the flower encloses a single erect orthotropous sessile ovule with 

 broad base, and with no other investment than a simple integument, w^hich is drawn 

 out into a style-like tube with a margin expanded in a discoid manner ; the nucleus 

 however has no embryo-sac, or is sterile. In the female flowers the perianth is 

 tubular, greatly compressed, somewhat winged, and altogether undivided; there is 

 no indication of any male organ ; the ovule (in this case of course possessing an 

 embryo-sac) is entirely enclosed in the perianth, and is similar in its external form 

 to that of the male flower, but with this difference, that the elongated point of the 

 integument is only simply slit, not expanded into the form of a plate. When 

 ripe the cone is about two inches long and of a scarlet colour; the scales are 

 persistent ; the perianth enlarges considerably and becomes broadly winged ; its 

 cavity is narrowed above into a narrow canal, through which the apex of the in- 

 tegument, passes. The seed is of the same form as the unfertilised ovule, and con- 

 tains abundant endosperm, in the axis of which lies the dicotyledonous embryo ; the 

 embryo is thick at the radicular end, and is there attached to the very long spirally 

 coiled suspensor. The formation of endosperm commences in the embryo- sac even 

 before fertilisation ; archegonia are formed which grow out of the embryo-sac to the 

 number of from twenty to sixty, and penetrate into the canal-like cavity of the 

 nucleus; there they are fertilised by the pollen-tubes which have grown to meet 

 them, the pro-embryos being then formed in the lower part of the central cells, the 

 (coiled) suspensors attaining a length of three inches. Although from two to eight 

 archegonia are fertilised, only one embryo is developed. 



7/je Formation of Tissue in Gymnosperms. From the abundant though still unsifted 

 material I will only adduce a few particulars as a contribution to the special character- 

 istics of this section. 



The Fibro-'vascidar Bundles^ are similar in their structure to those of Dicotyledons. 



series are wanting and only the carpels remain. But in the male flower the carpels are anterior and 

 posterior, while in the female they are lateral. This is to be explained by the fact that the carpels 

 are here the first leaves of the branch, and that it is very rare (except in Grasses) that the first leaves 

 of a shoot are anterior or posterior, and not lateral. The ovular integument of the female flower is 

 wanting in the male. While therefore the male flower is complex, the female is remarkably simple. 

 For further details see Transactions of the Linnean Society 1873, vol. XXVIII, pp. 507-512. 

 — Ed.] 



Mohl, Bau des Cycadeenstammes (Verm. Schr. p. 195).— Kraus, Bau der Cycadeen-Fiedern 



