5134 Annelid es. 



pleasure and profit the letters of your correspondents at Perth, who, from their proxi- 

 mity to the breeding-ponds at Stormontfield, where the greatest experiment in pisci- 

 culture ever undertaken is being carried on, from their laudable desire to give every 

 information, and from their rigid adherence to facts observed by themselves, have 

 done more towards clearing up this much-vexed question than could have been hoped 

 for. It would appear from the letters in the last ' Field' that the experiment is by 

 no means completed. Let us hope that the noblemen and gentlemen, proprietors of 

 the Tay fishings, who have already done so much, will not relax in their exertions till 

 the experiment is fully carried out. There is much to be discovered yet; and it is to 

 be regretted that no distinctive mark can be put upon the young fish now about to 

 depart from the breeding-pond. Even at present there appears some confusion ; for 

 by the letter signed " Peter of the Pools'' it would appear that several of the young 

 fish were taken by force from the pond, and the same mark placed upon them as upon 

 those which left it voluntarily. This, I am afraid, may lead to error; because, should 

 any of these fish so taken and marked be retaken in the smolt state from the river 

 during the present season, it may leave a loop-hole for prejudice to carp at. I think 

 the experiment at Stormontfield does much to reconcile the theories of the two par- 

 ties, one of whom asserts that the parr remain two years in the river, and the other 

 that they go away when only twelve months old. Mr. Young, of Invershin, turned 

 all his young fish into the river when they were twelve months old ; some of these 

 were retaken in the form of grilse the same season ; but how can he be certain they 

 all went to the sea? Some of them certainly did, because they came back grilse; but 

 it is quite impossible he can prove they all went. Here his experiment agrees with 

 that at Stormontfield ; for, had all the young fish been expelled from the pond, it 

 might have been concluded they all went to the sea, because some of them would 

 have returned. Shaw, on the other hand, might possibly have detained fry which 

 would have gone and returned had they been permitted. I can see nothing that cannot 

 be reconciled between the two theories. The sporting world, the angler, the natu- 

 ralist are greatly indebted to you for the irresistible evidence you have brought for- 

 ward, and the impartial manner in which you have opened your columns to all 

 comers who chooss to write like gentlemen. — Extracted from the Field newspaper. 



The Horse-leech (Hsemopsis sanguisuga) Swallowing a Worm. — I trust there are a 

 few of the junior readers of the ' Zoologist' to whom the fact I am about to relate is 

 as new as it was to myself: I had been one morning to the canal in order to obtain 

 materials for the "Tittlebat theory" propounded at page 5124 of this present 

 ' Zoologist,' — a theory which one of these days may possibly vie with that of my illus- 

 trious predecessor in these abstruse researches, the immortal Samuel Pickwick, — and 

 having returned home laden with water- weed and worms, tinkers and tadpoles, leeches 

 and larvae, I popped one of the leeches into a tank, and one of my progeny, constant 

 companions of all my piscations, popped one of the worms into the same tank. The 

 leech almost immediately fastened on one end of the worm, which by its writhing, poor 

 thing, seemed strongly to object to tlie seizure: this writhing soon attracted the 

 attention of a juvenile perch, who forthwith sallied out from the ombrageous shelter of 



