FEBRUARY 25, 1904] 
NATURE 387 
regularly recurrent stable forms which constitute a 
species. We are inclined to think that this idea, ex- 
tended to the study of multicellular forms, would show 
that many so-called species are based on transient 
‘* modificational ’? ephemeromorphs. 
There is a dignified candour in Dr. Bastian’s attitude 
towards sceptics. ‘‘ It will doubtless 
imagination, seeing that others observe no such 
phenomena, and that my experience is altogether ex- 
ceptional.”’ To this he answers (1) that many recorded 
phenomena, referred without proof to infection by para- 
sites, are more simply interpretable as heterogenetic ; 
(2) that he has seen the numerous cases he has recorded 
because he has diligently looked for them through many 
years; and (3) that, after all, his photographs of trans- 
formations have to be explained somehow. We must 
confess that the photographs, ‘‘ engraved and printed,”’ 
appear to us no more than a plethora of puzzles and 
futilities of delineation. The method is obviously ad- 
mirable in being impersonal, but it seems to us quite 
ineffective in showing the transformation of the roti- 
fer’s or tardigrade’s ova into infusorians. But we can 
only state our own impression; others may see more in 
them than we can detect; perhaps the eye of faith will 
see much. 
““Some of my critics have refused to give any ade- 
quate consideration to the work because it has not been 
entirely done under certain impossible conditions which 
they would prescribe.’’ Dr. Bastian admits that he has 
not uniformly isolated the organisms under process of 
change or placed them in a sterilised medium. Such 
cataclysmal interference would inevitably stop the 
heterogenetic progress. He declares, however, that the 
observations in proof of the heterogenetic origin of 
bacteria and their allies ‘‘ have been conducted with all 
necessary precautions against the possibility of infec- | 
” 
tion.’’ If so, and every experimenter will agree that it 
is a big ‘‘if,’’ then the bacteria did arise by hetero- 
genesis, or they were present, though unseen, from the 
first. 
continuously watch the alleged heterogenetic changes 
from start to finish on the same individual organism, it 
is answered that the method pursued was that usually 
followed in embryological research—that of observ- | 
different in- | 
different states of change in 
The method is comparable to that of 
ing 
dividuals. 
of phyletic change; it is not absolutely demon- | 
strative, but it reveals phenomena which must 
be interpreted somehow; and the best and most 
reasonable interpretation, ‘‘ as much as possible irre- 
spective of preconceptions and a priori views,’’ seems to 
the author that of heterogenesis. If it be urged that 
Dr. Bastian should have watched the heterogenetic pro- | 
cesses he believes in with the same sort of assiduous 
continuity as Dallinger and Drysdale achieved in study- 
ing their plastic monads, it is answered that ‘‘ com- 
pliance with such demands would not only be fruitless 
but would go far to render for ever impossible any 
knowledge of heterogenesis.’? Why this should be so 
NO. 1791, VOL. 69 | 
be said that the | 
facts I have brought forward are mere figments of my | 
| out controversy over spontaneous generation. 
| careful study of Dr. Bastian’s book, we venture to 
To the critic who asks why Dr. Bastian did not | 
- F : - | Jubelband—Wilhel 
paleontologists in working out a presumed series | Ju eae es ws 
we do not understand, unless heterogenesis be like the 
building of the fairies’ palace which always stopped if 
anyone looked at it. But the fact is that ‘“‘ the methods 
employed by those who would gain a knowledge of 
heterogenesis cannot, from the very nature of the sub- 
ject, be strict laboratory methods ’’—and this, we fear, 
will foreclose the question in the eyes of most biologists. 
For our part, the suggestion of foreclosing a ques- 
tion like this savours of prejudice, and it should be 
remembered that results of great value, both theoreti- 
cally and practically, have issued from the long drawn 
After a 
:—(1) If the 
generalised, 
sum up our impressions as - follows 
idea of heterogenesis means, 
that may be marked 
transilience, or per saltuwm change in the 
when 
there discontinuity, or 
ceaseless 
process of organic variation, then we side with the 
author, and in this regard he will find that he has 
many allies. (2) In so far as the idea of heterogenesis 
implies that many of the lowest forms of life are very 
plastic creatures of circumstance, capable of passing 
from phase to phase of the cell-cycle under modifica- 
tional stimulus, so markedly that they may be called 
** ephemeromorphs,’’ we again side with the author, for 
we think that there are many facts which point in this 
direction. (3) As to the thesis that simple organisms 
“are ever seething up anew by processes of hetero- 
genesis,’’ it seems to us, in our ignorance, a quite legi- 
timate conception which may eventually be demon- 
strated as true. (4) But as to the majority of the cases 
of heterogenesis which Dr. Bastian adduces, we can- 
not but reject them as inconclusive, not only because 
the methods employed seem to us to be fallacious, 
especially in depreciating the possibilities of latent 
germs and of infection; not only because they lead us 
to conclusions which we cannot harmonise with our 
confessedly incomplete biological system ; but especially 
because they are so meaningless. If the egg of the 
Hydatina can, ‘‘ under conditions not always easy to 
realise,’’ be transformed into a large ciliated in- 
fusorian, then our Systema Naturae is a farce. 
PROF. OSTWALD’S JUBILEE. 
Ostwald. Gewidmet zur Feier 
seiner vor fiinfundzwanzig Jahren erfolgter Doktor- 
promotion von seinen Schilern, mit einer Einleitung 
von J. H. van ’t Hoff. Pp. xxxi+679. (Zeitschrift 
fiir physikalische Chemie, Band 46.) 
HIS stately volume is a fitting tribute to an eminent 
man who has done much to advance the progress 
of modern chemistry. The triumvirate, van ’t Hoff, 
Arrhenius and Ostwald, the Dutchman, the Swede 
and the: Russo-German, had a hard battle before their 
doctrines were accepted by physicists and by chemists. 
The communications made in the first volume of 
Ostwald’s Zeitschrift by van ’t Hoff (p. 481) on the 
réle of osmotic pressure in the analogy between liquids 
