NOVEMBER 29, 1906 | 
NAT ORE 
q 
‘varieties are crossed, the character of. one of the 
parents is commonly alone visible, but the (different) 
‘character of the other is really present, though latent, 
in the offspring. On again crossing the latter these 
latent characters reappear, and often in a very definite 
proportion, in this second generation. 
This fact was discovered many years ago by 
Mendel, and has formed the basis of most of the 
recent experimental work that has thrown so much 
light on the problems of heredity. But although it 
harmonises, in a large number of cases, with the 
expectation based on a study of nuclear division, there 
are many things which still require explanation. Prof. 
Strasburger has touched on some of these; thus, for 
instance, the proportion of the sexes in many uni- 
sexual plants and animals is an almost invariable 
one, and appears to be inexplicable on the view of 
the chromosomes above indicated. On the other 
hand, we know, especially amongst animals, of cases 
in which the sex of the offspring can be definitely 
affected by conditions that are under control, although 
further study is necessary for their thorough elucida- 
tion. The assumption of entirely new characters 
again provides a field of research that as yet can 
hardly be said to have been explored at all except 
statistically, and it is at the same time one that is 
certain to yield most profitable fruit. 
These and many other points are raised in the page 
of a booklet which, while of small dimensions, is 
replete with material for thought. Prof. Strasburger 
has shown that a popular exposition does not neces- 
sarily connote a superficial treatment of a difficult 
subject. J BE. 
Ss 
Ss 
DISEASE AND ITS PREVENTION. 
(1) Immunity in Infective Diseases. ‘By Prof. Elie 
Metchnikoff. Translated from the French by 
Francis G. Binnie. Pp. xvi+591. (Cambridge: 
University Press, 1905.) Price 18s. net. 
(2) The Inflammation Idea in General Pathology. 
By. Dr We He Ransom? E-R.S- Pp. vi+354- 
(London: Williams and Norgate, 1905.) Price 
7s.’ 6d. 
(3) The Milroy Lectures on Epidemic Disease -in 
England. The Evidence of Variability .and_ of 
Persistency of Type. By Dr. W. H. Hamer. Pp. 
Gp (London :. Printed at the Bedford Press, 20 
‘and 21 Bedfordbury, W.C., 1906.) . . 
(4) Microbiologie Agricole. By Dr. Edmond Kayser. 
Pp.. xii+439. (Paris: Librairie J. B. Bailliére et 
Fils.) Price 5 francs. - : 
(1) ATHOLOGISTS. will welcome this translation 
< _of Prof. Metchnikoff’s great . work on 
immunity, containing as it does the results of twenty 
years’ work devoted to the subject. Commencing 
with some introductory remarks on the importance of 
immunity, the author passes on to review the pheno- 
mena of immunity in unicellular animals and in multi- 
cellular plants, the resorption of formed elements and 
of albumenoid fluids in animals, instances. and 
mechanism of natural immunity against | micro- 
organisms, the problems of acquired immunity against 
NO. 1935, VOL. 75 | 
oo 
micro-organisms and of natural and artificial 
immunity against toxins, and the comparative 
immunity’ of the skin and mucous membranes to 
microbial attacks. A chapter on protective vaccin- 
ations, and another giving a useful summary of the 
whole subject and an historical sketch of our know- 
ledge of immunity conclude the volume. 
The dominant idea running 
book, and supported with the 
ingenuity, is that the of defence of the 
organism against the invasion of micro-organisms 
lie principally, if not entirely, with certain of the 
wandering cells of the body, ‘‘ phagocytes,’? which 
comprise some of the leucocytes, and probably also 
certain endothelial and fixed connective tissue cells. 
These phagocytes either directly attack the invaders, 
enveloping and digesting them (phagocytosis), or, in 
the case of toxins, unite with these and prevent their 
toxic action, or secrete, or produce as a result of 
their disintegration, substances which are bacterio- 
lytic and bactericidal for micro-organisms, and 
occasionally antitoxic for toxins. Under natural 
conditions it is chiefly against the microbes, and not 
against their toxins, that the organism has to defend 
through the whole 
greatest ability and 
means 
itself, and hence phagocytosis normally is all- 
important. It used to be supposed that the body 
fluids were bactericidal, and the blood serum in vitro 
frequently possesses marked bactericidal properties, 
but Metchnikoff and his co-workers, particularly 
Gengou, have shown that the blood plasma in such 
cases before coagulation has occurred is almost 
devoid of bactericidal power, but after coagulation 
the breaking down of leucocytes which accompanies 
this phenomenon apparently gives rise to the bacteri- 
cidal substances in the serum. 
There is little to criticise in the book. It is some- 
what difficult to grasp exactly what cells Prof. 
Metchnikoff regards as phagocytic, as his nomen- 
clature of the leucocytes differs essentially from that 
used by most pathologists. In the chapter on pre- 
ventive inoculation Haffkine’s. anti-choleraic inocula- 
tion is criticised in a manner hardly justified in view 
of the excellent results shown by the: statistics of 
Simpson: and others. In certain places the state- 
ments are not quite up to date, since the book in 
the original was published in 1gor. 
The volume is fascinating’ reading; and anyone 
who first dips into it will in all probability do more, 
and study it deeply. It forms a complete statement 
of the phagocytic hypothesis, and a masterly summary 
of the whole subject of immunity up to 1902. 
(2) It is somewhat difficult to grasp exactly what 
the author of this book wishes to impart to his 
reader. Apparently it is his desire to formulate a 
conception of inflammation which shall be applicable 
to all organisms, animal and vegetable. The author 
believes that pathologists have always considered that 
inflammation is the first stage towards repair after 
an injury. But this is hardly so; it would be more 
correct to say that pathologists hold that the pheno- 
mena of inflammation generally tend towards repair, 
which is a conception distinctly different from that 
assumed by Dr. Ransom. According to him, an 
