OUR BOOK SHELF. II 
Decomposition or Diffluence—Reproductive Phenomena, Binary 
division or fission—External and Internal Gemmation—Sporular 
multiplicities—Sexual or Genetic reproduction—Affinities of the 
Infusoria to the higher Zoological groups—Distribution of the 
Infusoria—Preservation of the Infusoria—winding up with the 
Methods of Investigation. 
Amongst the above is to be found a careful account of the 
coloring matter of these organisms, including the bright red 
corpuscles of uglena, described by Ehrenberg as optic organs, 
with mention of Professor E. Ray Lankester’s researches upon the 
spectroscopic appearance of these tinctorial substances. 
The fourth chapter on Spontaneous Generation is exceedingly 
well put together; the masterly researches of Messrs. Dallinger 
and Drysdale, of Liverpool, are detailed at some length with those 
also of Professor Tyndall, and it would be well if all those who hold 
similar views with Dr. Bastian would read in this treatise how that 
the germs of Cercomonas typica, Heteromita rostrata, with those of 
other species, “when first released by rupture of the enclosing cyst 
are of such extreme minuteness as to defy individual resolution 
with the one-fiftieth inch objective and associated magnifying power 
of no less than 15,000 diameters.” 
A glance at Plate XI. in Part II., and reference to p. 41 in 
Part I, brings us to debatable ground—we refer to the position 
accorded to Myxomycetes, and here termed Mycetozoa. ‘This 
fungal division may be studied to the best advantage in Sach’s 
Handbook of Botany issued by the Clarendon Press, and we are 
bound to confess that pages of matter which tell us that those 
bodies we have so long regarded as fungi, such as Didymium 
Trichia, Stemonitis, Arcyria and Physarum require much inception 
ere we can bring our minds to believe them animals, for the reason 
that at one period of their existence they produce moving or 
zoospores. 
The difficulty of separating Protophytes from Protozoa by a clear 
line of demarcation is still as great a task as ever, and the simple 
transfer of a family from one side to the other does not settle the 
question. We cannot say there is any natural boundary, at least at 
present, and an artificial one must needs be open to human error. 
It must not be forgotten that Dr. De Bary (partly upon whose 
evidence it is, that the Myxomycetes have been transferred to the 
Protozoa) was once caught tripping with regard to the resting spores 
of Peronospora—might it not be that his visual organs have been 
deceived in this instance also. 
