i78 
Notes. 
have simple hairs 1 , and I. agree with Schumann 2 in placing them 
together in a separate order, the Elaeocarpaceae, characterized chiefly 
anatomically 3 by the absence of mucilage-receptacles (which occur 
abundantly in almost all holopetalous Tiliaceae) and of stellate 
hairs. 
The ovary of Plagiopteron is trilocular and contains two basal 
collateral ovules. This arrangement of the ovules is to be found in 
Brownlowia, a member of Bentham and Hooker's first tribe, Brown- 
lowieae, in which the ovules are always limited in number. Further 
the resemblance between the buds of Plagiopteron and Brownlowieae 
is most striking, especially with regard to those of Berrya and 
Brownlowia. All have a valvate, slightly gamosepalous calyx, which 
is small in comparison with the valvate corolla, differing in these 
points considerably from the buds of Elaeocarpaceae. The stamens 
of Plagiopteron are curious in that they open by four apical pores, and 
it is partly owing to this mode of dehiscence of the anthers that 
Warburg (loc. cit.) refers Plagiopteron to the Elaeocarpaceae. It 
seems to me, however, that we can hardly compare the short, globular 
anthers of our genus with the greatly elongated ones of Elaeocarpaceae. 
On the contrary, I think that we could more readily compare them 
with the anthers of Brownlowieae, although I do not attach very much 
importance to this point at all. The anthers in the latter tribe 
dehisce by two lateral valves, which are frequently confluent at the 
apex. If we imagine these lateral valves to become gradually more 
apical, we should finally arrive at a dehiscence by two broad apical 
pores, as is sometimes found in Plagiopteron. 
On the whole, I think that Plagiopteron would be best placed 
amongst the Brownlowieae. It has already been mentioned that 
practically all holopetalous Tiliaceae are provided with mucilage- 
receptacles (Schleimbehalter) in mesophyll and cortex. One genus 
( Pityranthe ) of the Brownlowieae makes an exception to this rule, so 
that the fact that they are also wanting in Plagiopteron need not dis- 
concert us. Finally, with regard to the opposite leaves of this genus 
it may be pointed out that they often show a marked tendency to 
1 Stellate hairs are said to occur in certain species of Sloanea, although I have 
not come across them as yet. 
2 Cf. Engler-Prantl, Natiirl. Pflanzenfamilien ; Nachtrage zu iii. 6, 1897, p. 230. 
3 The writer is occupied with an investigation of the anatomy of this order, of 
which one or two general results have just been mentioned. 
