The Embryo-Sac and Embryo of certain Penaeaceae. 
BY 
E. L. STEPHENS, 
Newnham College , Cambridge ; 1851 Exhibition Scholar, South African College , and Queen Victoria 
Scholar , University of the Cape of Good Hope. 
With Plates XXV and XXVI. 
T HE Penaeaceae are a small family of shrubby Dicotyledons, of an eri- 
coid habit, entirely confined to the south-west region of Cape Colony. 
The order has yet to be studied from a systematic standpoint, but five 
genera, with twenty-two species, are recognized by Gilg 1 — Sarcocolla , 
Penaea , Br achy siphon, Endonema , Glischrocolla. Of these, I have investi- 
gated the following species, representing three of the genera — Sarcocolla 
squamosa , S', fucata , X. formosa , Penaea mucronata , P. ovata , Br achy siphon 
imbricatus. Of Endonema and Glischrocolla I have not yet been able to 
obtain material suitable for embryological work. All the species investi- 
gated show exactly the same life-history, and the account that follows may 
be taken as applying to them all. Material was collected for the most part 
on the slopes of the mountains of the Cape Peninsula during 1907, and 
again during a visit to S. Africa from July to September, 1908. Material of 
Geissoloma marginata , belonging to the allied order Geissolomaceae, was 
collected for comparison at Garcia’s Pass in the Langeberge Mountains 
in September, 1908, during an excursion, kindly arranged by Prof. 
Pearson for that object ; information as to the exact locality of this very 
rare plant was obtained through the kind agency of Dr. Marloth. The 
material examined was fixed in acetic-alcohol (two parts of absolute 
alcohol to one of acetic acid), mercuric chloride (solution in one per cent, 
acetic acid), various chromo-acetic mixtures, or Fleming’s solution. The 
best results for nuclei and for mature embryo-sacs at about the fertilization 
period were given by the acetic-alcohol mixture ; in the free nuclear stages, 
however, this fixative caused contraction (cf. PI. XXV, Fig. 14) ; for these 
and for the developing embryo, the chromo-acetic and Fleming’s solution 
1 Gilg, in Engler and Prantl, 1894, p. 208. 
[Annals of Botany, Vol. XXIII. No. XCI. July, 1909.] 
