458 
NATURE 

[ Océ. 5, 1871 

Tunicata inter se, or otherwise to be the larval conditions of 
higher forms. My own observations, however, recorded in the 
ast July number of the ‘‘ Quarterly Journal of Microscopical 
Science,” have led me to believe that they are the free swim- 
ming reproductive Zooids of higher Tunicates, bearing the same 
relation to them as many free swimming Jfeduse do to some 
stationary hydroid colony. At the greater depth of 600 and 
800 fathoms, various species of Zérebratu/e were taken as re- 
presentative of the class Brachiopoda. 
Ascending yet higher to the subkingdom of the Mollusca, a 
large variety of interesting species rewarded our researches. In- 
cluded among these were—/usus contrarius, a common fossil of 
the Norfolk crag recently discovered in the living state in Vigo 
Bay by Mr. M‘Andrew, and dredged by us in the same lo- 
cality ; also a species of Cassis, remarkable from its being more 
closely allied to C. Sadwron and other species inhabiting the 
Japanese and Chinese seas than to any of its Mediterranean or 
Atlantic congeners. This circumstance of ‘its affinity is the 
more remarkable when associated with the occurrence of a 
species of Hyalonema (H. lusitanica) off the samecoast, likewise 
scarcely distinguishable from the more familiar Japanese form 
4. Sieboldi. 
The Annelida and Crustacea have also furnished a fair quota 
of new and interesting species, to be reverted to hereafter ; and 
neither taking a step further onwards to the higher vertebrate 
sub-kingdom has good fortune entirely deserted us Availing 
ourselves, through the kind assistance of Prof. du Bocage, of the 
aid of the native fishermen and their appliances, we secured 
examples of several rare species of the deep-sea ground-sharks 
frequenting the Portuguese coast line ; and among others a fine 
specimen of Pseudotriakis microdon, a species recently discovered 
and described by Prof. du Bocage and his gifted collaborateur, 
Felix de Brito Capello. 
Generalising from the whole amount of material collected 
during our cruise off the Iberian coast, our plunder may be 
separated into two very distinct groups. One of these, includ- 
ing that collected from the shore line down toa depth of 100 
fathoms, presenting an interblending of Mediterranean species 
with those prevalent on our own more temperate coasts. Among 
these former I may more especially mention the occurrence of 
Dendrophyllia ramea, a well-known Mediterranean branching 
coral in great luxuriance at the mouth of the river 
Sado, this being, I think, the first record of this coral 
being taken so far north, and also from the same locality 
Calappa granulata, Maia verrucosa, Murex trunculus and bran- 
daris, Cestum veneris, Veritillum cynomorium, and numerous 
other species belonging to the various Invertebrate divisions 
usually regarded as confined to the same more souther area. 
The residue and far smaller assemblage of species embraces those 
derived from the abyssal depths of from 400 to 800 fathoms, and 
all these, including many forms new to science, are characterised 
by their boreal or cold area facies, and in this respect con- 
tribute further evidence in support of the deductions arrived at 
by Dr. Carpenter, from his own more extended researches into 
the fauna of these same great depths in connection with the im- 
portant expeditions of the Porcupine and Lightning, and with 
which his name and those of his indefatigable colleagues, Prof. 
Wyville Thomson and Mr. Gwyn Jeffreys, are so worthily con- 
nected. 
In conclusion, it is my sincere hope that the rich reward at- 
tending our own humble efforts may stimulate other yacht 
owners to follow the example of my esteemed friend, Mr. Mar- 
shall Hall, influencing them likewise to devote their craft for one 
or a portion of a season to the cause of science, and to the explo- 
ration of those new deep-sea fields of discovery, now waiting to 
yield up the richest treasures to each earnest worker. Such men 
will find themselves more than compensated for the sacrifice of 
time or other interests by the fascinating nature of the work 
they undertake, in addition to earning for themselves the lasting 
gratitude of the scientific world. 
Our well-appointed and expensively-fitted-out Government 
expeditions should explore the remoter depths; but British 
pluck and private enterprise should esteem it their especial pri- 
vilege to unfold to us the yet hidden mysteries of the ocean world 
nearer home ; and if, again, all shall not succeed in discovering 
new phases of animal life, there is much and even more impor- 
tant work to be effected in ascertaining accurately the bathys 
metrical range and geographical limits and distribution of those 
forms already known to us. 
W. SAVILLE Kent 

PROF. BASTIAN ON THE GERM THEORY* 
FLPIDEMIC and acute diseases have many characters in com- 
mon ; they constitute a family the members of which are 
united by a certain bond of unity, though at the same time they 
are in other respects strikingly ditferent from one another. The 
‘*general” character of the symptoms originally gave rise to the 
notion that these affections were in the main dependent upon 
changes in the nature and quality of the blood. This view is 
still the one most commonly entertained, and which seems most 
likely to be true. And seeing that particular sets of symptoms 
recur with as much definiteness as individual differences of con- 
stitution will permit, we have a right to believe that the changes 
in the blood—however induced and of whatsoever nature they 
may be—are definite and peculiar for each of these diseases. The 
successive changes in the blood which are the immediate causes 
of the phenomena of small-pox, must be quite different from 
those giving rise to the morbid state known as typhoid-fever. 
Variable as these several groups of symptoms are amongst them- 
selves in individual cases, yet is there a general resemblance 
which suffices to maintain the distinctive nature of each affection. 
In this broad sense they are undoubtedly entitled to rank as 
“*specific” diseases. They may be presumed to be associated 
with definite changes in the blood, though we have nota right to 
infer that such changes of state can only be induced in one way. 
Many well-known chemical changes are capable of being brought 
about by more than one agency. And just as there is the best 
reason for believing that cancer or tubercle may be initiated de 
novo by the operation of irritants upon the tissues of certain indi- 
viduals, and that such growths may subsequently be multiplied 
within the body by the contact-influence exerted by some of 
their disseminated particles ; so may we suppose, not only that 
specific substances (contagia) may be capable of initiating specific 
changes in the blood, but that certain combinations of circum- 
stances may by their action upon the human body entail similar 
definite changes and states of blood. Having to do with a per- 
verted nutritive activity and mode of growth in a limited area 
of tissue, cancer or tubercle may make their appearance; whilst, 
having an altered nutritive activity and set of changes occurring 
in the blood, this all-pervading tissue may lapse into the succes- 
sive states peculiar to one or other of the specific diseases, and so 
give rise to the symptoms by which they are characterised. This 
is by no means a forced analogy. Can cancer or tubercle arise 
in the individual without any pre-existing ‘‘ hereditary taint ” ? 
Can the states of blood peculiar to the several specific diseases 
arise de ovo, or independently of contagion? These are ques- 
tions whose import is really similar.t __ 
One of the great and distinguishing peculiarities of these 
specific diseases is their ‘‘contagiousness.” Although very 
differently marked in the several affections, this property is as 
interesting as it is important. The fact of its existence seems 
always to have had a large share in determining the nature of 
the general views which have been held concerning these affec- 
tions. Even in remote periods, by Hippocrates and others, they 
were commonly compared to processes of fermentation ; whilst 
since the time of Linnzus, more especially, attention has been 
often prominently directed to the many apparent similarities ex- 
isting between the commencement and spread of epidemic 
diseases, and the ‘flight, settlement, and propagation of the in- 
sect-swarms which inflict blight upon vegetable life.” These 
* Extracts from Introductory Lecture on Epidemic and Specific Contagious 
Diseases : Considerations as to their Nature and Mode of Origin. Deli- 
vered at University College, October 2, by H. Charlton Bastian, M.A. 
M.D., F.R.S. " 
+ This double mode of causation is perfectly familiar to the chemist 
Particular chemical changes may occur under the influence of certain 
general determining conditions, which at other times (ir. the absence of these 
conditions) may be even more easily initiated by a single specific cause. The 
introduction of a crystalline fragment into a saline solution, and its determi- 
nation of the crystallisation of all the isomorphous salts contained in the 
solution, seems to be exactly comparable with the “‘ contagious” origin of 
diseases. But, under the influence of certain favouring conditions, crystalli- 
sation may occur without the contact of a crystalline fragment—the process 
may be “‘ spontaneous” in the same sense that the occurrence of the blood- 
change may be “spontaneous.” 
t Sir H. Holland’s ‘‘ Medical Notes and Reflections,” 2nd edition, 1840, 
p- 584. On the following page, the same author writes:—“ Connected with 
these facts is the observation, seemingly well attested, that the cholera some- 
times spreads in face of a prevailing wind, and where no obvious human 
communication is present—a circumstance difficult, if indeed possible, to be 
explained, without recourse to animal life as the cause of the phenomenon. 
No mere inorganic matter could be so transferred, nor is vegetable life better 
provided with means for overcoming this obstacle.” Whilst on the preceding 
page, the “‘animal species” had been admitted to be ‘ minute, beyond th¢ 
reach of all sense,” 
