THE SCOTTISH MARINE STATION AND ITS WORK. 235 



a semi-parasitic fish allied to the lamprey, is not uncommon 

 on the east coast, and is a great pest to the fishermen by 

 devouring the cod on the lines or taking the bait from the 

 hooks. It is, however, an object of great interest to zoolo- 

 gists, from its exhibiting several very primitive characters in 

 its orga.nisation, which render a knowledge of its develop- 

 mental history a great desideratum. It has long been known 

 that the mature egg is contained in a hard, horny husk, at 

 either end of which is a bunch of stiff processes like bristles, 

 but with two or three hooks at the end of each ; hitherto 

 only two such eggs have been found,* and Mr. Cunningham, 

 in spite of numerous efforts and much expenditure of time 

 and money, was unable to obtain more, even by keeping adult 

 animals for months in an aquarium, so he took advantage of 

 the opportunity offered by his having numerous specimens 

 at his disposal to make a careful investigation of the deve- 

 lopment of the reproductive products, which has led to some 

 interesting results. The horny envelope of the egg appears 

 to correspond to the so-called ^' zona radiata " of the egg of 

 other fish, that is to say, it is a primary egg-membrane and 

 not an extraneous growth. Male specimens are exceedingly 

 rare, but in the great majority of those in which the eggs 

 are immature the hinder part of the generative gland is a 

 well formed testis ; and Mr. Cunningham is inclined to think 

 that these immature animals are functionally males and that 

 most eggs are fertilised by them. 



A department of knowledge in which science is at present 

 very backward, is that which relates to the eggs and young 

 stages of food-fishes ; this inquiry was successfully prosecuted 

 by Mr. Cunningham, and the results of his work, containing 

 not only descriptions and figures of the eggs of about a 

 dozen species, but also an account of previous researches in 

 this direction, have been published by the Eoyal Society of 

 Edinburgh. At the time of his departure from Granton, 

 Mr. Cunningham was engaged in a systematic and anatomical 

 study of the Annelida of the Firth of Forth, a work which 



* Dr. Fridtjof Nansen has just informed me that he has discovered a third 

 egg among the stores of the Bergen Museum, which was dredged thirty years 

 ago by Dr. Danielssen near Molde. 



