IOO 
Notes . 
external influences on the hiophors and determinants* (p. 415). 1 These 
very minute fluctuations \i. e. continual changes of composition in the 
elements of the germ-plasm ] which are imperceptible to us , are the 
primary cause of the greater deviations in the determinants which we 
finally observe in the form of individual variation ’ (p. 417). 
Finally, I must express my regret that so careful a technique 
and such powers of observation as the author’s should have been 
overweighted with a priori and obsolete views. It is not good 
to follow too literally the adage ‘ Eher eine schlechte Hypothese 
als gar keine.’ 
Queen’s College, Cork, 
Feb. 14, 1896. 
MARCUS HARTOG. 
STUDIES IN THE MORPHOLOGY OP SPORE-PRO- 
DUCING MEMBERS. PART II : OPHIOGLOSSACEAE h— 
In a paper published in the Philosophical Transactions (Series B, 
1894), the comparative study of the spore-bearing members of the 
Lycopodineae, including the Psilotaceae, has led to the conclusion 
that there is reasonable probability that septation of sporangia 
originally simple, to form synangia, has taken place ; that a septate 
body (synangium) may be homologous with a non-septate body 
(simple sporangium) ; and that there is no essential difference between 
tissue which will form septa or trabeculae, and that which will form 
spores, since the tissues can mutually undergo conversion one into the 
other. 
But the considerations there brought forward do not amount to an 
actual demonstration that septation has occurred. For the purpose 
of our discussion, it is important to ascertain whether such demon- 
stration can be given in the case of parts which are undoubtedly 
homologous ; it is afforded by the study of septate anthers, which 
occur in several distinct families of Angiosperms, e. g. Mimoseae, 
Onagraceae, Loranthaceae, Myrsineae, Rhizophoreae, Orchidaceae, 
Rafflesiaceae. Taking the case of the Onagraceae, the common type 
of the anther is the ordinary quadrilocular type, but in certain genera 
transverse septa are formed in each of the four pollen-sacs by conver- 
1 Read before the Royal Society, Dec. 5, 1895: reprinted by permission from 
Proc. Roy. Soc., No. 354, Vol. lix. 
