95^ APPENDIX. BOOK IT. 



Page 478. An interesting abnormality has been observed by Goebcl (Bot. Zeitg. 

 1879) in Isoetes lacustris and echinospora. In a number of specimens no sporangia had been 

 developed on the leaves, but in the place of each sporangium a young plant had been 

 produced by budding. 



Page 481, seventh line from top. For * delevopment ' read ' development.* 



Page 495, line 18; for ^ Cocus' read ^ Cocos.* 



Page 504. Cycadeae. On the development of the pollen sacs and pollen of Zamia 

 murkatay see Treub, Ann. d. Sci. Nat, ser. 6, t. XV, 1882. 



Page 506. Treub {loc. cit.) makes the following statements with regard to the 

 development of the ovule of Ceratozamia longifoHa. 



Each scale of the female cone bears two sporangiferous lobes, in each of which a 

 macrosporangium is developed. 



The macrosporangium is visible in the lobe before any external differentiation can 

 be detected. 



The macrosporangium subsequently consists of a group of sporogenous cells (arche- 

 sporium ?), surrounded by an external parietal layer and by an internal parietal layer 

 consisting of several rows of cells. 



Only one of the sporogenous cells gives rise to a macrospore. This cell undergoes 

 no further division, but constitutes the single macrospore in the manner in which the 

 embryo-sac is generally formed. 



Shortly after the differentiation of the macrosporangium in the interior of the 

 sporangiferous lobe, two new bodies are formed on the lobe superficially to the macro- 

 sporangium ; these are the integument, and a mass of tissue immediately over the macro- 

 sporangium which Treub terms the nucellus. 



The macrosporangium is, according to Treub, perfectly homologous with a 

 sporangium of Ophioglossum ; the nucellus and the integument are therefore new forma- 

 tions which have no equivalents in Cryptogams. 



Page 519, line 6 from top. For ' are ' read ' is.' 



On the Morphology of the female flower in the Coniferae, see Eichler, Ueb. die 

 weiblichen Bliithen der Goniferen, in Monatsber. d. k. Akad. d. Wiss., Berlin, 1881. As 

 the result of comparative investigation of the female flowers in the various families of 

 Coniferae, he concludes that in the Araucarieae, Abietineae, and Taxodineae each cone is a 

 single flower, and that the scales of the cone are simple leaves (carpels) bearing ventral 

 outgrowths (seminiferous scales) on which the ovules are borne ; in the Cupressineae the 

 ovules are borne in the axils of the carpeilary leaves ; in the Taxineae (incl. Podocarpese) 

 the ovules are borne on the carpeilary leaves [Microcachys, Dacrydium, Podocarpus)y in 

 Phyllocladus they are axillary, in Taxus and Torreya they are terminal on lateral shoots, no 

 carpels being present. In these two genera each ovule represents a single female flower, 

 whereas in all the other genera and families the female flower consists of an aggregate of 

 carpels bearing ovules either directly or in their axils. Eichler considers that Taxus and 

 Torreya lead from the Coniferae to the Gnetaceae. 



Eichler finds that it is no longer possible to hold Celakovsky's view that the ovule is 

 either a modified leaf or a bud. (See note, p. 574, on the morphological significance of the 

 placenta and of the ovule.) 



Page 526, top line; for ^ Juniperus^ read ^Thuja.^ 



Page 530. Gnetaceae. On the Embryology of the Gnetaceae, see the paper by 

 Bower, Q^J. M. S., 1882, of which the following is a brief abstract: — 



It appears to be the rule in Gnetum Gnemon (though not in all species of the genus) 

 that the embryo is not developed until the seed begins to germinate : long tubular 

 suspensors are however found in the endosperm of the ripe seed. On germination, em- 

 bryos are formed at the apices of these suspensors, the mode of their development being 

 similar to that which obtains in other Gymnosperms. It has been observed that the 

 suspensors branch and that an embryo is developed at the extremity of each branch, 

 a curious form of polyembryony : only one of the numerous embryos persists. 



