282 The American Geologist. November, isas 
ner nucleus of irregular granular caleite which repeats the form of 
the rods only on a smaller scale ; therearound is laid a shell of un- 
usuall}' regular zonal and radial structure, exactly after the fashion 
of the true 0(')lites. A foreign inner nucleus is never present, and 
the rather long, as well as always uniform shape of these prodig- 
iously abundant bodies confirmed me in the belief that they are 
organic forms, despite the fact that the structure of the shell af- 
forded me no point of support for it. Now, my supposition of 
that time gains much in probability because the agreement with 
the or)lite rods of the Salt lake is one quite remarkable. 
But structures analogous to the irregularly granular alga-lime- 
stones of the Salt lake also seem to occur in older formations. I 
refer especially in this statement to the so-called ' ' great 0()lite 
structure" of the Wettersteinkalk. 
The structure of certain calcareous or)lites which Wethered and 
most recently also Bleichor (May, 1892) have investigated .seems 
to me to have great resemblance to that of the Sinai oolite and 
is, perhaps, to be explained in the same manner. 
In the highest degree remarkable are the 12 // long rodlets which 
Bleicher has rendered visible in the iron oolites by treatment with 
aqua regia. He regards them, if possible, as bacteria (Comptes 
Rendus Acad. Science. Paris. March, 1892). If their plant- 
nature be established, they might also be claimed as fission-algai. 
According to the present stage of my researches, I am inclined 
to believe that at least the majority of the marine calcareous 
oolites with regular zonal and radial structure are of plant ori- 
gin : the product of microscopically small algse of very low rank, 
capable of secreting lime. 
8 Juli, 1892. 
THE IMMEDIATE WORK IN CHEMICAL SCIENCE.* 
Ai.T'.EiiT B. Pbescott, Ann Arbor. 
A division of science has a work of its own to do, a work that 
well might be done for its own sake, and still more must be done 
in payment of what is due to the other divisions. Each section 
of our Association has its just task, and fidelity to this is an obli- 
gation to all the sections. Those engaged in any labor of science 
owe a debt to the world at large, and can be called to giA^e an ac- 
* Retiring address as President of the American Association for the 
Advancement of Science, August, 1893. 
