March 2, 1871] 
NATURE 
343 

Poissons” of Cuvier and Valenciennes, like too many 
other French publications, has never been finished. 
When Dr, Giinther commenced his labours in 1859, 
his work was apparently intended to be confined to the 
Acanthopterygian order of fishes, and the volumes were 
entitled accordingly. On the completion of this great 
order with the third volume in 1861, the scope and title of 
the publication were extended so as to embrace the whole 
class of fishes. The fourth volume, issued in 1862, was 
devoted to the Pharyngognathi and Anacanthini of Miiller, 
whose system Dr. Giinther has generally followed. Here, 
however, he has made a slight change in the nomen- 
clature used by the great German Anatomist, considering 
that the structure of the fins is of more importance than 
that of the pharyngeal bones, and therefore changing 
Miiller’sname, “ Pharyngognathi acanthopteri” into“ Acan- 
thopterygii pharyngognathi.’ ’ 
In the fifth volume of his work, issued in 1864, Dr. 
Giinther commenced the order Physostomi, treating first 
of the Siluroids and allied forms, which were formerly 
associated with the Salmonidz ; in the sixth, published 
two years later, the Salmonidz themselves were handled. 
This group, Dr. Giinther informs us, both on its own 
account and from the large amount of literature involved 
in its investigation, offers such great difficulties to the 
ichthyologist, that “‘as much patience and time are required 
for the investigation of a single species of it as in the 
case of other fishes for that of a whole family.” The 
ordinary method followed by naturalists in distinguish- 
ing and determining species is here utterly inadequate ; 
and Dr. Giinther does not hesitate to assert that “no one, 
however experienced in the study of other families of 
fishes, will be able to find his way through this labyrinth 
of variations without long preliminary study, and without 
a good collection for constant comparison. Sometimes 
forms are met with so peculiarly and so constantly 
characterised, that no ichthyologist who has seen them 
will deny them specific rank; but in numerous other 
cases one is much tempted to ask whether we have not 
to deal with a family which, being one of the most re 
cent creation, is composed of forms not yet specifically 
differentiated.” 
Dr. Giinther’s preliminary remarks (vol. vii. p. 3), before 
he commences the discussion of the true Sa/mones, 
well merit perusal by any naturalist engaged on the differ- 
entiation of species. In the Salmonidz, characters such 
as the proportion of one part of the body to another, 
and the number of fin-rays, which in other groups of 
fishes are generally employed for the separation of 
species, fail entirely, and another set of characters has 
to be relied upon. To add to the confusion, some of the 
species at least énterbreed, and “it is probable, although 
at present not yet confirmed by direct observation, that 
such hybrids mix again with one of the parent species, 
thereby producing an offspring more or less similar to 
the pure breed.” The difficulties thus added to the 
correct determination of the Salmonidz, may be easily 
understood. 
The seventh volume of Dr. Giinther’s work, published 
in 1868, continues the history of the order Physostomi, 
and is devoted mainly to the extensive families Cypri- 
nidz and Clupeide, and to smaller groups nearly allied to 
them, In the eighth and last volume, published last year, 

Dr. Giinther concludes the Physostomi with the eels and 
their allies, and then treats of the Lophobranchii and 
Plectognathi, which form the two last orders of the Tele- 
ostian subclass of fishes. The small subclass Défno7, 
embracing only the two Lepidosirens, comes next, and to 
them is appended a short notice of the recent discovery of 
thenew Australian Mud-fish, which Mr. Krefft has referred 
to the Agassizian genus Cevatodus.* Dr. Giinther states 
his inability at that period to determine whether it “ should 
be referred to the Dipnoans or to the Ganoids, or should 
form the type ofa separate subclass.” But it is well known 
that he has since received perfect examples of this won- 
derful fish, and has in preparation a memoir which will, 
no doubt, put at rest all questions upon its structure and 
its position in the natural series. 
The Ganoids (of which, formerly multitudinous, subclass 
Dr. Giinther only recognises szx existing species) and the 
Chondropterygians, or Sharks and Rays, follow next in 
order, and the eighth volume concludes with the two 
undoubtedly lowest forms of the class of fishes—the 
Lampreys and the Lancelet, an zzvertebrated vertebrate. 
The total number of specimens of fishes in the collection 
of the British Museum at the period of the close of this 
great work was, as we have already said, 29,275. These 
are referred by Dr. Giinther to 5,177 species. Besides 
these, 1,666 other species are recognised as valid, 
of which the national collection has not yet obtained 
examples, and 1,682 more are referred to as doubtful. 
“Assuming, then,” says Dr. Giinther, “that about one 
half of the latter will ultimately be admitted into the sys- 
tem, and that since the publication of the volumes of this 
work, about 1000 species have been described elsewhere, 
we may put the total “number of fishes at present knowa 
as about 9000.” 
In the preface to the last volume, Dr. Giinther, besides 
giving us a general vésumé of the extent of the collection 
under his charge, enters very fully into several other 
questions which are well worthy of attention, particularly 
at the present moment, when the relations between 
Government and Science are undergoing investigation by 
a Royal Commission. Whilst expeditions, fitted out by 
Austria, Prussia, and Italy, are despatched round the globe, 
accompanied by a staff of naturalists, and bringing back 
large collections of fishes to the national museums, our 
navy, it appears, is almost inert on this subject. Except 
from the Magellan Straits Surveying Expedition, to which 
Dr. Cunningham was attached as naturalist, no contribu- 
tion from our Admiralty, which has so many ships always 
afloat, has reached the ichthyological department of the 
British Museum of late years. Yet it cannot be doubted 
that a very few words of encouragement from my Lords 
of the Admiralty would induce some of the many naval 
officers whose time must hang heavy on their hands at 
foreign stations, to turn their attention to collecting the 
common objects of theelement on which they pass their lives. 
Weassume, of course, that the expense of attaching acompe- 
tent naturalist to any foreign expedition would be so great 
that “my Lords would not fel justified in incurring it /” 
Yet even the economical government of the United States 
thinks differently, and “each exploring American expe- 
dition was and still is accompanied by collectors, employed 
solely for the benefit of public museums.” 
* See Nature, vol. ii. p. 106. 
