12 Fi^/ieri/ Board for Scotland. 



An interval of fovir to six hours in quiescent watei' has. however, 

 usuall}^ been i^iven to allow of the ova becoming fastened to the i^lass. 



The glass plates can be put into wooden boxes, each holding 

 about six plates. The boxes may be put in a herring barrel into a 

 frame, which can be revolved from time to time. The barrel would, 

 if necessar}^ be surrounded with ice during the railway journey. 

 The spawn should be protected from the light. 



For the woodwoi'k, I think cual-tar is a suitable preservative. 



PLATE I. 



Fig. 1. Drawing (plan) of apparatus ior conveyance of herring spawn. 

 1a. ,, (section) ., ,, 



2. Drawing of apparatus in wliicli the cooled lierring spawn was kept 

 during the Spring of 1911. 



3. Enlarged drawing of part of enibyro, to show crystals in gut. 



4. Live egg attached to dead egg, showing large number of crystals. 



5. Enlarged drawing of crystal. 



6. Enlarged drawing of anterior end of a larva, which had been retained in 

 the egg until much of the yolk had l)een absorbed. 



7. Enlarged drawing of a sperm. 



8. Different shaj^es assumed by unfertilized eggs when they fell on the 

 glass plate. 



9. Drawing to show the corpuscle which alternately blocked and receded 

 from the heart of the embryo partially shown in fig. 3. 



10. Egg in which crystals had appeared within 36 hours of spawning. 



LETTERS USED. 



a. — Anus. 



o: — Crystal. 



de. — Dead egg, 



dmf. — Dorsal marginal tin. 



fjt. — Grllt. 



le. — Live eim. 



nt. — Notochord. 



o. — Outer skin of zona. 



pi. — Glass plate. 



t. —Tray. 



vmf. — A'entral marginal fin. 



;//.•.*— Yolk. 



