i88 7 .] 
A Protandric Hermaphrodite. 
9 
Not knowing Thompson's description,Prof. Japetus Steenstrup 
of Copenhagen published, in »Oversigt over det k. danske Vidensk. 
Selskabs Forhandlinger «, 1863, an account of a specimen of Myxine 
which contained mature eggs. This specimen was found amongst a 
number sent to the Museum of Copenhagen, in September 1862. 
The mature eggs were enclosed in a corneous shell with horny threads 
at the ends, as also described by Thompson. Those eggs, in the 
Museum of Copenhagen, are the only ova regarding which we know 
with certainty where, and how, they were obtained. Steenstrups 
paper was published as a guide to any who might attempt to 
compete for the prize, offered by the Academy of Science of 
Copenhagen, for the elucidation of the problem of the reproduction 
and development of Myxine. The Academy has never yet had the 
oportunity arlorded it to award the prize. 
Owen (1866) also gives, in his Comparative Anatomy of the 
1 Vertebrates (vol. I, p. 598) an illustration of a mature egg of Myxine. 
Dr. Gunther mentions, referring to Steenstrup's paper, the 
eggs of Myxine in his » Study of Fishes« in the British Museum 
Catalogue, and in his article Ichthyology in the »Encyclopædia 
Britannica« 9th edition. 
Prof. Robert Collett in his memoir » Norges Fiske « (Kristi- 
ania 1875) mentions eggs of Myxine; those eggs are, however, as 
also stated by Cunningham, immature eggs originally tåken from 
the ovaries of the animals. 
In 1875, the first important account of the minute histological 
. structure of the generative organs of Myxine was given in Wilhelm 
.Muller's paper: »Ueber das Urogenitalsystem des Amphioxus 
und der Cyclostomen« (Jenaische Zeitschrift Bd. 9). The author 
states that Myxine is dioecious, and he describes and illustrates 
the ovaries as weli as the immature testes, which it is evident from 
his illustrations, as well as from his very distinct description, that 
he has closely examined. As it has special interest for the present 
paper, I will quote, in extenso, his account of the males and the 
male organs. • 
»Was die Angaben Joh. MØLLERS iiber die Beschaffenheit des 
Hoden betrifft, so entsprechen dieselben so wenig dem wirklichen 
Befund, dass ich zweifelhaft bin, ob Johannes Muller wirklich das 
Mannchen von Myxine glutinosa vor sich gehabt hat. Die Mann- 
chen sind viei seltener als die Weibchen und wie ich Grund habe 
: zu vermuthen, etwas kleiner; alle månniichen Exemplare, welche 
:ich erhielt, wurden ganz kurz nach dem Aussetzen des Koders ge- 
