INFUSORIA. 
245 
Richmond to Ehrenberg, and he will doubtless determine to what extent the African and 
American beds agree in their microscopic fossils. As the infusorial strata of Virginia belong 
decidedly to the tertiary epoch, and yet appear to agree remarkably with what Ehrenberg 
considers as chalk marl from Oran, a revision of the evidence upon which the siliceous infu¬ 
sorial conglomerates of Africa and the south of Europe were referred to the cretaceous group, 
appears necessary. Should the true age of either the American or African deposits be deter¬ 
mined by means of the fossil infusoria, it will be an additional instance of the importance of 
this branch of microscopic palaeontology. It has been well remarked that the microscope is 
now as important an instrument for the geologist as the hammer; and indeed the results 
obtained by microscopic observation of coal, fossil wood, teeth, polythalamia, and infusoria, 
prove the truth of this remark. The question cui hono ? to what useful end are your pur¬ 
suits ? can now be triumphantly answered by the lover of microscopic research; but happily, 
to use the words of the Hon. W. H. Harvey,* the class who now ask this question to natu¬ 
ralists “ is neither so numerous nor respectable as it was two years ago; it is becoming every 
day less so, and will soon be confined to the ignorant and the sensual.” In the language of 
another distinguished philosopher,! “ the time is past when the utility or dignity of such pur¬ 
suits can be affected by a sneer at the littleness of their objects, as they seem little in the eyes 
of the indifferent and the ignorant. Every thing is great or small only by comparison ; the 
telescope teaches us that the world is but an atom, and none know better than microscopical 
observers that every atom is a world.”! 
* Manual of British Algae, by the Hon. William Henry Harvey, 
t Richard Owen, Esq. Address before the Microscopic Society of London, 1841. 
t American Journal of Science, Vol. 43. 
