NATURE 385 
THURSDAY, FEBRUARY 25, 1904 
HETEROGENESIS. 
Studies in Heterogenesis. By H. Charlton Bastian, 
M.A., M.D:,° F.R.S. ' Pp. 1X+354+Xxxvil; 19 
plates, with 815 illustrations from photomicrographs. 
(London: Williams and Norgate, 1903.) Price 
31s. 6d. 
ETEROGENESIS means, in these studies, the 
per saltum origin of forms of life from other 
quite different forms, e.g. of a ciliated infusorian from a 
rotifer’s egg, or of a sun-animalcule from a chlorophyll 
corpuscle. It is long since Dr. H. Charlton Bastian 
first suggested this heresy; and many years of indus- 
trious observation have resulted in this large and ex- 
pensive volume describing and (with 815 figures) illus- 
trating those cases in which the author thinks he has 
detected the heterogenetic process at work. One can- 
not but admire the doggedness with which Dr. Bastian 
has persisted—contra mundum—in maintaining his 
thesis; and even those who feel quite sure that he has 
misinterpreted what he saw may find it interesting to 
discover by repetition of his experiments what did 
actually occur and was actually photographed. Others, 
again, who would not turn round to look at slides sup- 
posed to demonstrate that the egg of a rotifer may re- 
solve itself into infusorians or into one large ciliate, 
may be more tolerant of the suggestion that Protistan 
evolution is still going on, retracing some of its ancient 
steps, or making new ones. It may be that Proteus 
still frisks a little among the Protists, or that there 
are mutations among unicellulars just as among De 
Vries’s evening primroses. 
It is often said by biologists that biogenesis (or the 
origin of approximately like from like) is not so much 
a law as a fact. It may not have always been, it may 
not everywhere be, that a living creature arises only 
from a parent or parents like itself; but, so far as our 
experience goes, the biologists say, there is no exception 
to this rule. Here, however, we have a book which is 
full of such exceptions, and yet the author’s papers on 
this subject are rejected by the Royal Society of London, 
the Académie des Sciences of Paris, the K. Akademie 
der Wissenschaften of Berlin, and the R. Accademia 
dei Lincei of Rome! What does this mean? Does it 
mean more than that the author’s rejected addresses 
appeared to the secretaries and committees of these 
learned bodies as incredible, as the recent facts and 
theories relating to radium would have seemed not long 
ago? ‘* What can hardly be distinguished from per- 
petual motion, which it is an axiom of science to call 
impossible, has,”’ says Prof. Boys, “‘ left every chemist 
and physicist in a state of bewilderment.’? Thus, as 
the question rises in our minds, whether heterogenesis 
may not be an unknown factor in evolution, we turn to 
what Dr. Bastian has really done. 
(1) The author believes that he has shown the de novo 
origin of bacteria within “ closed cells,’’ e.g. of fruits 
or in a Structure like a caudal seta of Cyclops. In the 
last case, two or three days after death, ‘ scarcely 
visible motionless specks gradually appear in the | 
structureless protoplasm,”’ they grow into bacteria and | 
| 
NO. 1791, VOL. 69] 
| organic infusions. 
show active swarming movements. ‘‘ In such a case it 
is clear that we have to do with no process of infection 
from without, but with a de novo origin of bacteria 
from the protoplasmic contents of the spines or setz.”’ 
But this interpretation is quite unnecessary ; it has been 
shown beyond doubt that bacteria may exist in fluids 
where the highest powers of the microscope fail to de- 
tect them, many organisms normally swarm with bac- 
teria, and the possibility of infection from without also 
remains. 
(2) Another set of experiments, which appear to us of 
greater value, are concerned with the ‘ proligerous 
pellicle *? or zoogloea that forms on the surface of 
Apart from his conclusions, which 
means, of course, leaving Hamlet out of the play, Dr. 
Bastian’s study of the surface pellicle, apparently a very 
hotbed of life, is a very interesting contribution to 
microbiology. From such a pellicle, which seems to 
consist solely of aggregates of bacteria, come fungus 
““germs,’’ amoebe, flagellate monads, and even 
ciliated infusorians like vorticellids. Some of the trans- 
formations are described and photographed from stage 
to stage, and a point is made of the diversity of results 
obtainable from similar pellicles. But, so far as we can 
see, no progress in proving heterogenesis can be made 
along this line. From what seems to be a homogeneous 
pellicle of discrete corpuscles there arise all sorts of 
animalcules, and Bastian argues in favour of hetero- 
genesis because they were not there before ; while to the 
majority of biologists the emergence of the amcebze and 
infusorians simply proves that they were, in minute 
form, there before, or were added to the pellicle from 
above or from below in the course of the transform- 
ation. 
It is a familiar fact that a small sample of water from 
a brook may show in many representative drops no 
evidence of living organisms of any kind, even when 
examined under very high magnification. But in this 
sample after a week or two there are not merely 
microbes, but monads, flagellates, and even ciliates. 
The enthusiast on behalf of heterogenesis concludes 
that the new tenants arose from ultra-microscopic 
animate particles or from non-living material; the 
ordinary humdrum biologist concludes that he over- 
looked in his sample the juvenile forms of the now 
obvious tenants, or that his expedients to avoid infec- 
tion from without were insufficient. But, prejudice 
apart, it seems a little like a non possumus argu- 
ment on both sides until we inquire into the familiar 
control experiments of boiling or otherwise sterilising 
the samples, and then the advocate of heterogenesis 
is forced to say that such cataclysmal operations as boil- 
ing prevented the inorganic potentialities from assert- 
ing themselves. This savours strongly of the explan- 
ation of a séance failure by the presence of sceptical 
spirits. It may be that in both cases the objection is 
valid, but when a full-fledged vorticellid emerges in the 
sample, or when the summoned spirit reveals an 
acquaintance with the canards of the daily Press, we 
fall back into utter scepticism in regard to both hetero- 
genesis and spiritualistic séances. 
(3) Many other heterogenetic modes of origin—of 
fungus ‘ erms,”’ of amcebe, of monads, of Actino- 
= s' 
S 
