xii 
Transactions of the Royal Society of South Africa. 
Mr. Chakles Willian Mally, M.Sc, F.E.S., F.L.S., proposed by 
Joseph Burtt-Davy, Chas. P. Lounsbury, W. A. Caldecott, K. T. A. 
Innes, R. B. Young and Robert A. Lehfeldt, were elected Fellows of the 
Society. 
Ordinary Meeting. 
An Ordinary Meeting was held on Wednesday, September 26th, 1917, in 
the Board Room of the South African Association, Church Square, Cape- 
town. 
The President, w^as in the Chair. 
The Minutes of the previous Ordinary Meeting were confirmed. 
Miss E. L. Stephens exhibited specimens of eleven parasitic plants 
belonging to the genera Cassytha, Hydnora, Viscum, Striga, Loranthus, 
Hyobanche, Harveya and Sarcophyte, and made some brief remarks on 
their structure and biology. 
Communications : 
"Note on the Abnormal Development of the Genital Organs of Jasus 
Lalandii.'' By W. von Bonde. 
The author records a peculiar abnormality in a male Cape Crawfish. 
Three distinct genital apertures are developed, two normally, and a 
third abnormally, the latter occurring on the fourth walking leg of the 
right side. 
Internally the vas deferens of the right bifurcates, sending a branch to 
the normal opening and a second to the abnormal aperture. 
" On the Colour-Octahedron as a Complexity " : being suggestions 
towards a Mathematics of Colour. By Gr. H. Malan. 
Developing certain ideas of Meinong, who contends that the possibility 
of representing certain well-known facts in connection with Colour-Psycho- 
logy ^ diagram in the form of an octahedron rests on the presence of 
certain a priori relations incidental to the very nature of colour itself, the 
writer is led to examine Meinong's contention critically in the light of 
modern Mathematical Logic (as expounded by B. Russell). The result of 
this examination is (1) to show that Meinong's theory, though true in its 
intention, is seriously at fault in its practical conception of an a priori 
science of colour, because of the ignorance of its author of the principles of 
mathematics as revealed Vjy recent researches of mathematicians, and (2) 
to necessitate a more exact discrimination between the standpoints of 
Empirical Psychology and Mathematical Science. In order to sustain his 
negative criticism of Meinong's " Greometry of Colours," the writer then 
endeavours to prove that the formal relations obtaining between colours are 
the very same as those with which mathematics is ordinarily conversant, 
