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ROYAL MICROSCOPICAL CLUB. 405 
for their successive appearance in the fluid, without supposing 
that one form was developed out of another, ¢. e. without having 
recourse to the startling hypothesis of heterogenesis. Their 
observations, they are bound to say, gave no countenance to this 
doctrine. On the contrary, the life-cycle of a monad is as 
rigidly circumscribed within defined limits as that of a mollusc 
orabird. There is no indication of any unusual or more intense 
methods of specific mutation than those resulting from the secular 
processes involved in the Darwinian law, which is held to furnish 
the only legitimate theory of the origin of species. 
They do not agree with Billroth as to the sameness or 
monotony of specific forms in putrefying animal matter. This 
may be true in the earlier styles of putrefaction, but not in the 
later, when flagellate forms appear, sometimes extinguishing 
the bacteria and their congeners, and play, as the authors believe, 
an important part as active agents of putrefaction. 
The life-cycle of several forms having now been traced, it is 
seen that in no instance was the continuance of the species main- 
tained without the introduction of a sexual process, a blending 
of what were shown in the sequel to be genetic elements. 
The experiments as to the effect of heat on the monads and 
their spores uniformly established an important fact, viz. 
_that the spores resist heat much better than the adults. A 
temperature of 150° EF. was always found to destroy utterly all 
the adult forms, while the spores resulting from sexual genera- 
tion have a power of resistance to heat which is greater than this 
in the proportion of eleven to six on the average. ‘“ This appears 
to us,” they say,” to be the very essence of the question of Biogenesis 
versus Abiogenesis. In some, at least, of the septic organisms 
spores are demonstrably produced, and these spores can resist a 
temperature nearly double that of adults on the average; that 
which some can resist is 88° F. above the boiling point of water.” 
This is in harmony with the experiments of Roberts and the later 
ones of Huizinga. 
The President read a paper “ On some New Contrivances for 
the Study of the Spectra, and for Applying the Mode of Spectrum 
Analysis to the Microscope.” He exhibited and explained a new 
apparatus for employing an ordinary eye-piece in connection with 
a slit and prisms, and also the binocular spectrum microscope. 
Mr. Sorby still employs the quartz interference scale for the 
measurement of bands, but proposes for the future to adopt the 
plan now employed in the case of luminous spectra, and express 
everthing in terms of wave-lengths. For this purpose he has con- 
structed a table giving the wave-lengthsof every one-eighth division 
of his quartz interference scale, so that, having measured the 
position of any part of the spectrum by means of this scale, he 
can at once, by the table, express everything in terms of 
millionths of a millimeter of wave-length. He proposes to publish 
this table, and also the means of correction for other scales not 
accurately corresponding, so that every observer may express 
