Bibliographical Notices. 499 



He next describes the ova of Solea variegata, which measure 1"28 to 

 1-36 millim. in diameter, and differ from those of the common sole 

 in having oil-globules of considerable size scattered separately over 

 the yolk ; but the ova of Solea liitea, which are similar though 

 smaller (those measured by Mr. Holt being -78 to -84 millim.), liave 

 apparently not been captured near Plymouth, where young speci- 

 mens are " fairly common." 



In Part III. the geographical distribution of the soles and their 

 habits are considered. He speaks of the sole as rarely, if ever, cap- 

 tured by any other instrument than the trawl ; but, like the plaice, 

 it can be captured by the hook with suitable bait — some of the finest 

 examples at St. Andrews being procured in this way. His remarks 

 on the food of the sole are interesting and only require the addition 

 that the lobworm is a prominent feature in its dietary. 



In Chapter IV. an acc-oi;nt of the breeding of the sole is given, 

 and he is probably right that under certain conditions, as in the 

 flounder and plaice, a large part of the ovary ripens its contents 

 simultaneously. The spawning-period is lengthened — those in the 

 south, according to the author, spawning in February, March, and 

 April, while in Scotland the period ranges from May to August. 

 The small size of the testes of the male is remarkable, and the state- 

 ment quoted from Nordman that a species of sole adhered during 

 copulation is noteworthy. With the exception of the experiments 

 in the spring of 1890, as stated in the postscript, the hatching of 

 the soles at Plymouth was difficult. 



The author is of opinion that soles spawned in March have com- 

 pleted their metamorphosis by the middle of May, when they are ^ 

 to y^^ inch long, and that on May 31st the)' are | inch, and that in 

 one year they grow about 5 inches in length. Those 6| to 9| inches 

 are just over two years. He thinks that soles 14 inches long are four 

 years old, and those 20 inches long about six years. His diagnosis 

 in regard to the first 5-ear is, however, uncertain. 



Part IV. is devoted to what is called Economical subjects, and in 

 this part considerable condensation might have been eftected. In 

 artificial fertilization the author crushed the testes, as indeed is the 

 common plan with the gurnard and others at St. Andrews, and 

 which Dr. Wilson found equally satisfactory in the mussel. An 

 ingenious apparatus, slightly differing from Captain Chester's, of the 

 United-States Fish Commission, is figured and explained by the 

 author. Experience elsewhere shows that success can be obtained 

 with open vessels, and the more simple such apparatus is the better. 

 He is of opinion that a railway journey jolts and mechanically injures 

 the pelagic eggs ; but this may be exceptional, since in 1884, and 

 often since, ova fertilized far out at sea have afterwards been safely 

 sent by railway from distant places, such as Aberdeen or Macduff, 

 to St. Andrews. 



The author thinks that the sole-fishery is declining, and some 

 pungent remarks are made in regard to fishery statistics which were 

 only lately put on a ])roper footing — thanks to the late Lord Dal- 

 housie's Commission. He rightly suggests the desirability of fertil- 



