Scientific Investigations. 13 



of a different race, because after a single season's examination they 

 are seen to be, in general size or otherwise, different from those of 

 another locality about the same time or at difTerent seasons. To 

 decide as to this effectually, continuous observations over several 

 seasons is essential, and" he was conscious "that, in this respect." 

 his " own observations, although they had extended over three years, 

 were still insufficient : but at least they indicate how changed, in of 

 course a limited degree, the herrings of one and the same locality but 

 of different years may be. Much safer it is, where the difference 

 between individuals is so slight or so obscurely separated as not to 

 permit of a short examination clearly demonstrating its racial origin, 

 to doubt rather than infer its accuracy.'' He felt " pretty sure that the 

 variations just referred to are not permanent, but are due to the vary- 

 ing conditions of food and temperature affecting the young herring, 

 as well as to the probable variability in size and age of its parents." 



" The conclusion at which " he arrived " from these observa- 

 tions was that there is no true racial difference between the herrings 

 of the various localities around our coasts ; and while the investiga- 

 tion points towards a distinction between the herrings frequenting 

 our shores in summer and winter, it is so small, not only in its actual 

 extent, and more especially in the circumstance that there is no sharp 

 line of distinction between the two, but that many of the summer- 

 herring are found to be marked by the same characteristics as those 

 of the winter, that he did not feel justified from the investigation in 

 considering this to be a well-proved fact." 



Jenkins discusses Heincke's separation of the spring- and autumn- 

 spawning herrings. 



Suggestions as to Future Work. 



Heincke has shown that races exist among the herrings of Europe. 

 The problem is to extend and confirm his observations. 



It is not possible to say what is the best method to follow in in- 

 vestigating the race-problem. It may happen that a method which 

 is useful in separating two races which occupy very dissimilar en- 

 vironments may not be of equal value in separating shoals which live 

 under conditions that differ only slightly. 



It is probably well to carry out the investigation on lines similar 

 to those adopted by Heincke and Matthews, i.e. by means of a com- 

 parison made through body-measurements, enumeration-characters, 

 etc. 



Heincke recommended that the spawning-shoal be taken as the 

 starting-point for race-investigation, and there can be no doubt this 

 is the correct method. The adoption of this condition would furnish 

 fishes all of one class, and fully comparable inter se. 



The fishes should be spawning, or " full " fishes. Five hundred fishes 

 is suggested as the number that would give a suitable sample of the 

 shoal, but a larger number would probably be advantageous. Spawn- 

 ing herrings are those in which the reproductive organs are so far ripe 

 that the ova and milt issue by the genital pore when the abdomen is 

 gently pressed. In the event of spawning herrings not being available, 



