CHAIN OF CYCLOSALPA AFFINIS 439 
dent, Professor A. D. Bache, said in what we should now call his 
presidential address: 
The germ of two most important discoveries in natural history was 
contained in papers by two of our youngest members. [The first is 
omitted as not relevant.] Thecontents of the other were thus expressed: 
‘The order of succession of parts in foraminiferae is identical with the 
successive development of leaves in plants, and can be expressed by the 
same formulae.’ Such discoveries, just warm from the study, it may be, 
as in these cases, forced to light by the occasion of our meetings, are 
among our greatest triumphs in the way of advancement. (Proc., vol. 
4, p. 159.) ; 
We find no evidence that these ideas of Pourtales have been 
carried farther either by him or by any one else, though our ex- 
amination of the literature with reference to the point has 
been far from exhaustive. D’Orbigny, twenty-five years before, 
had done much work on the fundamental types of growth in 
the foraminiferae, though we find no reference to his having com- 
pared the arrangements here found, with phyllotaxy in plants. 
Our object in calling attention to this matter is, in the first 
place, to show that we are not quite alone in thinking such com- 
parisons are profitable; and in the second place, to call attention 
to the possibility that exact studies in the quantitative relation- 
ship existing among the members of a repetitive series as well as 
upon the ordinal arrangement of these members, may be profit- 
able. But should it be found that such studies are significant 
when prosecuted on unicellular organisms in which the segmen- 
tation does not go to complete severance of the pieces, it would 
seem to follow that they should also be significant when made on 
species in which the severance is complete, and then to all cell 
division whatever. 
This, of course, brings us immediately to the cyclical phenomena 
in the propagation of the Infusoria that has received so much 
attention in recent years, particularly at the hands of Maupas, 
Calkins, Jennings, Woodruff, and others. Concerning these 
researches we do no more now than remark that if the general 
conceptions on which we are going are sound, the phenomena of 
