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president’s address. 
Many curious facts have been observed in reference to the forms, 
or multiplication, or life-history of some of these parasitic beings. 
Thus, for example, in one class (Filaria sanguinis) it was noticed 
that the minute embryos of this little blood-worm could only be 
discovered in the evening or during the night, and not during the 
day ; and the reason of this has appeared to be that it is necessary 
that they should come within reach of the Mosquito Knat, 
which is a night-feeding animal, in Avhose bodies one stage of their 
development appears to take place. 
One of the latest discoveries in this department of natural 
history is that of the blood germs, which co-exist Avith the various 
forms of ague and malarious disease, and upon Avhich they would 
appear to depend. Dr. Osier of Pensylvania, has recently 
described and figured these little bodies in an elaborate paper 
full of interest. 
Such facts as these, Avhen regarded merely from the point of 
vioAV of a member of the Medical Profession have their deep and 
special significance. But I am here to-night as a member of the 
Naturalists’ Society, and by all of us, in that capacity, they are 
first to be regarded, not as illustrations of disease, but of the life 
history of some of nature’s creation-s, — creations Avhich are no 
doubt as important, as definite, and Avhich play as large a part 
in the general scheme of life, as do many of the larger forms 
of animated beings. 
Some of these little bodies, especially those of the bacillary and 
bacterial class, are extremely minute, and are best examined Avith 
poAvers ranging from one-tenth to one-tAventy-fifth of an inch ; and 
it is impossible to ignore the fact that their study requires not 
only good instruments, but much patience and skilled attention. 
Nevertheless, such study fairly comes Avithin the scope of this 
Society’s Avork, and Avill most certainly repay any of its members 
who may be induced adequately to undertake it. 
Nor let it be said that minuteness is any reason for lack of 
interest on the part of the naturalist. For many of these micro- 
organisms have already been shoAvn to be as varied, and to have as 
definite a structure, and as special a life history, as any of the 
