122 
Briefe. 
Oncidium flexuosum is a native of our district and so are the other Orchids of 
my garden, all of which I coUected in our Island and on the neighbouring continent. 
In the several cases of seifimpotent Orchids, in which poUen and stigma 
of the same plant have a poisonous action on each other, I never found a trace 
of parasitic cryptogams. 
To the list of these Orchids I may add a small Oncidium (probably un- 
described) from Theresopolis, in which own pollen after three days stay in the 
stigmatic Chamber was decayed and 
dark brown. This Oncidium grows 
in compagny of O. unicorne and 
though the flowers are quite dif- 
ferent the pseudobulbes and leaves 
of the two Speeles are about un- 
distinguishable. Perhaps this stränge 
ressemblance may be due to mimicry. 
I am now experimenting on the last 
(as to its flower-time) but not least 
of our Oncidia, the Oncidium crispum 
(Fig. 37), which will perhaps be an 
exception among our other self-im- 
potent species of that genus. At least 
after g days stay in the stigmatic 
Chamber of the same plant, the pollen 
and its tubes are perfectly fresh and 
healthy. 
I will give one more instance 
of the lessened fertility of Epid. cin- 
nabarinum when it is fertilized with 
own pollen. Jan. 17 I fertilized six 
flowers of a raceme with pollen- 
masses of the same flowers, and ob- 
tained six pods, the seeds of which 
weighed: 1.5, 2, 1.5, 2, 2.5 grains; 
most of the seeds were bad. 
On the same day I fertilized six 
flowers of a second raceme of the 
same plant with pollen of a distinct 
plant of the species and obtained 5 pods, the seeds of which weighed 5—6—5— 
5 — 5 grains, but few seeds being bad. 
At reading Dr. Hildebrand's paper on Corydalis cava which you have been 
so good as to send me, I was Struck by the circumstance that among the 29 cap- 
sules obtained by crossing of distinct plants, the seeds of which were counted, 
none had 4 seeds, while about half the number had from 5 to 7, the others 
from 1—3 seeds. May not this species be functionally dimorphic, the poor pods 
being the result of illegitimate unions? 
In the course of the last months I have been trying some experiments on 
the crossing of different species of Orchids. There is the same unaccountable 
Fig. 37- Oncidium crispum. i. 22. März 1867. 
2. 23. März 1867 (24 Stunden ; eigner Pollen). 3. 23. März 
1867 (48 Stunden; eigner Pollen). 4. 24. März 1867 
3 Tage; eigner Pollen). Durchschnitt durch den unteren 
Theil der Narbenkammer. 5. 28. März 1867 (6 Tage; 
eigener Pollen). Aus F. M.'s nachgelassenen Papieren. 
