610 
would, he presumes, associate it with those birds. “Like 
many other of these antipodean forms, it must be regarded 
as an anomaly ; it is, in fact, a Bzzivra, and nothing 
more, for it stands alone.” 
The Musk-duck has a lengthened, stiff, and leather-like 
appendage hanging from the under surface of the bill, 
and is the only member of the family which possesses this 
singular structure. Its lengthened tail, composed of 
twenty-four narrowed and stiffened feathers, is, no doubt, 
most serviceable to it in swimming and diving, The 
female does not carry the chin-lobe, and is very much 
smaller than the male bird. 
The Musk-duck is widely distributed on the Australian 
Continent, and also inhabits Tasmania. As Mr. Gould 
tells us, it frequents the bays and inlets of the sea, the 
upper parts of rivers, lakes, and secluded pools. ‘‘ More 
than a pair are rarely seen at one time ; often a solitary 
individual takes up its abode in some favourite pool, 
where it lives a life of complete seclusion, depending for 
its food and for its preservation from danger upon its 
powers of diving rather than upon those of flying. It is 
very difficult to shoot, as it dives instantly a gun is fired, 
so that the shot has hardly time to reach it. 
by the Zoological Society on February 8 last. They were 
not in good condition when received, and though the 
utmost care was taken of them, one of them is since dead. 
The other may be seen in one of the tanks at the end of 
the Fish-house. 
THE LIFE-HISTORY OF THE EEL 
jes persons interested in the mystery that until quite | 
NATURE 
[April 27, 1882 
tion of the eel; and they were followed by Albertus 
Magnus, Leuwenhoek, Elsner, Redi, and Fahlberg. 
It was in the eighteenth century that for the first time 
the roe of the female eel was discovered, A surgeon of 
Comacchio, named Sancassini, in 1707, sent the ovaries, 
as he thought, of an eel, to the celebrated naturalist 
Valisneri, who sent an account thereof to the Academy 
of Bologna. Prof. Valsalva appears to have doubted the 
correctness of this discovery, The discussion continued. 
Pietro Molinelli offered a large reward for a gravid eel. 
In 1777 an eel presenting the same appearance as the one 
described by Valisneri was sent to Prof. Monti, who, 
being indisposed for the investigation, gave it over to a 
set of his favourite pupils, aniong whom was Camillo Gal- 
vani. These students pronounced the anatomical appear- 
ance to be the same as described by Valisneri, and the 
specimen was sent to Prof. Mondini for his opinion, 
which was published in the Bologna Academy’s Txansac- 
tions, to the effect that the ovary described by Valisneri 
was only the swimming bladder in a diseased condition. 
But in connection with this opinion Mondini gave and 
illustrated by magnificent plates a good description, and 
a‘ { | demonstrations of the true ovaries of the eel as found by 
The male examples of this curious duck were purchased | 
himself. This classical work of Mondini has been often 
overlooked. Later, but quite independently of Mondini, 
the ovary of the eel was discovered by O. F. Miller 
Spallanzani’s investigations in 1792 threw doubts upon 
the discoveries of Mondini and O. F. Miiller, so that. 
when Prof. Rathke in 1824 described the ovaries of the 
eel as two cuff and collar-shaped organs on both sides of 
the backbone, he was everywhere in Germany (and is to 
recently hung over the life-history of the eel, will | 
find themselves under great obligations to W. Brown 
Goode for the very able and exhaustive account which he 
has quite recently published on this subject in the Bzdle¢in 
of the United States Fish Commission, based upon the 
scholarly work ot Jacoby, and from which we abstract the | 
following. The number of species described by some 
authors is very large. Dr. Giinther would seem to recog- 
nise only about twenty-five. Dareste still further reduces 
the number, making but four species in the genus Anguilla. 
A. vulgaris, occurring throughout the northern hemisphere | 
in the New and in the Old World, A. mowa and A. 
marmorata in the Indian Ocean, and A. m»egalostoma in 
Oceania, and he further declares that even between these | 
four the boundaries are not clearly defined. The habits of 
the eel are still not quite understood. So far as is known, it 
is the only fish, the young of which ascend from the sea to 
attain an imperfect maturity, and return to the sea to 
deposit their spawn. The economical value of the eel as 
a food fish has been now well established, and they easily 
admit of being artificially introduced into lakes and rivers. 
The reproduction of the eel has from the days of Aristotle 
given rise to the most wonderful conjectures and asser- 
tions. Leaving out of question such old theories as that 
the eels are generated from dew, slime, horsehair, and from 
the skins of old eels, it has been a matter of dispute for 
centuries whether the eel is an oviparous or a viviparous 
animal. The reproduction of the eel was a mystery to 
the learned Greeks. While they knew that other fishes 
deposited their eggs, no discovery of the eggs of eels was 
ever made by them. The Greek poets solved the mystery 
in an off-handed way; for as they were in the habit of 
assigning to Jupiter the paternity of all children not 
claimed by earthly fathers, so they attributed the pro- 
genitorship of the eels to the same Jove. 
With the revival of the study of the natural sciences in 
the sixteenth century, we find that investigators turned 
their attention with great ardour to this special subject, 
and such renowned investigators as Aldrovandi, Rondelet, 
and Salviani published elaborate treatises on the genera- 
a large extent to the present day) regarded as the dis- 
| coverer. The first picture of the ovary, after that of 
Mondini, and the first plate of the microscopical appear- 
ance of the egg of the eel was published in a dissertation 
by Hohnbaum Hornschuch in 1842, and the question of 
the ovary of the eel may be regarded as definitely settled 
by the publication by Rathke, in 1853, of a description of 
| a gravid female eel, the first and only specimen of such 
which had come up to that time into the hands of an 
investigator. 
The search after the roe in the eel was of much later 
date. In 1842 and up to 1872 the researches of several 
observers were unrewarded with success. 
Of the various mistakes made in this investigation Dr. 
Jacoby gives us aninteresting account. In the meanwhile 
the late Dr. Syrski, the Director of the Museum of Natural 
History at Trieste, had undertaken, at the request of the 
| marine officials at Trieste, to determine t..e spawning- 
time of the fishes of this region, and he devoted a good 
deal of his attention to the smadler eels. On November 
29, 1873, Dr. Syrski found in an eel, now preserved in the 
Museum at Trieste, which was fifteen inches long, a com- 
pletely new organ, which had never before been seen 
within an eel by any former investigator, although tens of 
thousands of eels had been zealously studied. Syrski 
published his discovery in the Proceedings of the Vienna 
Academy for April, 1874, and, according to all the re- 
searches up to this time made, there would seem the 
highest probability that this organ of Syrski is actually 
the long sought, but immature male organ. The investi- 
gation cannot be said to be complete until the presence 
of spermatozoa is determined ; but the recent discovery 
; of such in the similar spermaries of the conger eel, by Dr. 
| Hermes, of Berlin, is a strong confirmation. The eels 
with the Syrskian organ are smallerthan the females, and 
are to be found only in the sea and brackish water. They 
have a short and sharply-pointed snout. Their dorsal 
| fin is less broad, and not so high as in the females. 
This discovery of Syrski drew attention anew to the 
solution of the eel problem. Among others, the German 
| Fischerei- Verein in Berlin offered a reward of 50 marks to 
the person who should first find a gravid eel sufficiently 
| developed to satisfy Prof. Virchow of the fact. Herr 
vinaisincmapeeiill 
