1. SALMO. 9 



and that many males, from 7 to 8 inches long, have their sexual 

 organs fully developed, and that their milt has all the impregnating 

 properties' of the seminal fluid of a much older and larger fish. That 

 this Parr is not a distinct species — as has lately been again main- 

 tained by Couch — is fuilher proved by the circumstance that these 

 sexually mature Parrs are absolutely identical in their zoological 

 characters with the immature Parrs which are undoubtedly young 

 Salmon, and that no Parr has ever been found with mature ova*. 

 But whether these Parr produce normal Salmon impregnating the 

 ova of female Salmon, or mingle with the River-Trout, or whether 

 they continue to grow, and propagate their species as true Salmon, 

 are questions which remain to be answered. We may only add that, 

 as far as we know, barren old Salmon must be extremely scarce ; 

 the only sterile example we know of is the specimen hh mentioned 

 on p. 15. 



3. The question whether any of the migratory species can be re- 

 tained in fresh water, and finally accommodate themselves to a per- 

 manent sojourn therein, must be negatived for the present. Several 

 instances of successful experiments made for this purpose have been 

 brought forward ; but all these accounts are open to serious doubts, 

 inasmuch as they do not afi"ord us sufficient proof that the young fish 

 introduced into ponds were really young migratory Salnionoids, or that 

 the fuU-gi'own specimens were identical with those introduced, and 

 not hybrids or non-migratory Trout of a somewhat altered appear- 

 ance in consequence of the change of their locality. We have seen 

 the experiment tried at two places in South Wales, by the Rev. 

 Augustus Morgan and by W. Peel, Esq., of Taliaris; and in both 

 cases the Salmon and the pure Sewin died when not allowed to 

 return to the sea. However, the latter gentleman pointed out to me 

 that the hybrid fishes from the Sewin and the Trout survived the 

 experiment, and continue to grow in a pond perfectly shut up from 

 communication with the sea. In that locaHty neither these hybrids 

 nor the trout spawn. 



4. Although the majority of the mature individuals of a migratory 

 species ascend a river at a certain fixed time before the commence- 

 ment of spawning, others enter the fresh water at a much earlier 

 period, either single or in small troops ; and many appear to return 

 to the sea before they reascend at the time of the regular immigra- 

 tion. It is not improbable that one and the same individual may 

 change the salt for fresh water several times in the year. However, 

 this is the case in certain rivers only — for instance, in those falling 

 into the Moray Firth ; in others one immigration only is known 



* Some advocates for the opinion of the specific distinctness of the Parr pre- 

 tend, indeed, to have found female Parrs. Those fish which were pointed out 

 to me as females, were invariably specimens which had fed freely on the ova of 

 their congeners, and their stomachs had been regarded as the ovary ! Some 

 persons were even so anxious to convince me of the correctness of their opinion, 

 that they sent me specimens with ova in the abdominal cavity. On closer 

 examination, these fishes turned out to be immature 7)iale specimens, the ova 

 having been introduced by a cut into the abdomen said to have been made to 

 admit the spirit ! 



