April 2%, 1881] 



NA TURE 



611 



so far as I have seen, almost exclusively of herrings, under 

 six months old, and as the average size of whitebait 

 increases, from March and April onwards, until they be- 

 come suspiciously like sprats in the late summer, it may 

 be concluded that they are the progeny of herrings 

 which spawned, early in the year, in the neighbourhood 

 of the estuary of the Thames, up which these dainty 

 little fish have wandered. Whether it is the general habit 

 of young herring, even of those which are spawned in 

 deep water, to migrate into the shallow parts of the sea, 

 or even into completely fresh waters, when such are 

 accessible, is unknown. 



In the Report on Trawling (1863) we observe :— 



" It is extremely difficult to obtain any satisfactory 

 evidence as to the length of time which the herring re- 

 quires to pass from the embryonic to the adult or full 

 condition. L f the fishermen who gave any opinion on 

 this subject, some considered that a herring takes three, 

 and others that it requires seven, years to attain the full 

 or spawning condition ; others frankly admitted that they 

 knew nothing about the matter ; and it was not difficult, 

 by a little cross-examination, to satisfy ourselves that 

 they were all really in this condition, however strongly 

 they might hold by their triennial or septennial theories. 

 Mr. Yarrell and Mr. Mitchell suppose with more reason 

 that herring attain to full size and maturity in about 

 eighteen months. 



" It does not appear, however, that there is any good 

 evidence against the supposition that the herring reaches 

 its spawning condition in one year. There is much rea- 

 son to believe that the eggs are hatched in, at most, from 

 two to three weeks after deposition, and that in six to 

 seven weeks more (that is at most ten weeks from the 

 time of laying the eggs) the young have attained three 

 inches in length. Now it has been ascertained that a 

 young smolt may leave a river and return to it again in a 

 couple of months increased in bulk eight or tenfold, and 

 as a herring lives on very much the same food as a smolt, 

 it appears possible that it should increase in the same 

 rapid ratio. Under these circumstances nine months 

 would be ample time for it to enlarge from three to ten or 

 eleven inches in length. It may be fairly argued, how- 

 ever, that it is not very safe to reason analogically from 

 the rate of growth of one species of fish to that of 

 another ; and it may be well to leave the question 

 whether the herring attains its maturity in twelve, fifteen, 

 or sixteen months open, in the tolerably firm assurance 

 that the period last named is the maximum." 



On comparing these conclusions with the results of the 

 careful observations of the Baltic Commissioners, it 

 appears that we somewhat over-estimated the rate of 

 growth of the young herring, and that the view taken 

 by Yarrell and Mitchell is more nearly correct. For 

 supposing that the rate of growth after six months 

 continues the same as before, a herring twelve months 

 old will be nearly six inches long, and at eighteen 

 months eight or nine inches. But full herrings may be 

 met with little more than seven inches long, and they 

 are very commonly found not more than nine inches in 

 length.' 



Fishermen distinguish four states of the herring. Fry 

 or sile, when not larger than sprats ; malies, when larger 

 than this, with undeveloped roe or milt ; full fish, with 

 largely developed roe or milt ; and spent or shotten 

 fisb, which have recently spawned. 



Herring fry of the size of sprats are distinguished from 

 full fish not merely by their size, but in addition, by the 

 very slight development of the milt or roe, and by 

 the accumulation of fat in the abdominal cavity. Bands 

 of fat are found in the mesentery alongside the intestine, 

 and filling up the interspaces between the pyloric cKca. 



^ Ljungman ('" Preliminary Report on Herrings and Herring Fisheries on 

 the West Coast of Sweden," translated in U.S. Commision Report. 1873-5) 

 speaks of full herrings ready to spawn only ico-iio mm. (4 to 4i in.) long, as 

 observed by himself. 



Maties (the name ' of which is a corruption of the Dutch 

 word for a maiden) resemble the fry in these particulars ; 

 but, if they are well fed, the deposit of fatty and other 

 nutritive matter takes place, not only about the abdominal 

 viscera, but also beneath the skin and in the interstices of 

 the flesh. Indeed, when nourishment is abundant, this 

 infiltration of the flesh with fat may go so far that the 

 fish cannot readdy be preserved and must be eaten fresh. 

 The singularly delicate Loch Fyne herrings are in this 

 condition early in the season. When the small crusta- 

 ceans, on which the maties chiefly feed, are extremely 

 abundant the fish gorge themselves with them to such 

 an extent that the conical crop becomes completely 

 distended, and the Scotch fishermen give them the name 

 of "gut-pock herrings," as much as to say pouch-gutted 

 fish, and an absurd notion is current that these herrings 

 are diseased. However, the "gut-pock" herrings differ 

 from the rest only in having their pouch full instead of 

 empty, as it commonly is. 



As the fish passes from the matie to the full condition, 

 the milt and roe begin to grow at the expense of the 

 nutriment thus stored up ; and, as these organs become 

 larger and occupy more and more space in the abdominal 

 cavity, the excess of nutritious substance is transferred to 

 them. The fatty deposit about the intestine and pyloric 

 CEeca gradually disappears and the flesh becomes poorer. 

 It would appear that by degrees the fish cease to feed 

 at all. .At any rate, there is usually no food in the stomach 

 of a herring which approaches maturity. In all these 

 respe.ts there is the closest resemblance between the 

 history of the herring and that of other fishes such as the 

 salmon— the parr correspnding to the herring fry or sile, 

 the grilse and the " clean fish " of larger size to the 

 maties. 



At length spawning takes place, the accumulated nutri- 

 tion, transformed into eggs or spermatic fluid, is expelled, 

 and the fish is left in that lean and depauperated state 

 which makes a "shotten herring" proverbial. In this 

 condition it answers to the salmon " kelt," and the milt 

 or roe are now shrunk and flaccid and can be blown 

 up with air like empty bags. If the spent fish escapes its 

 myriad enemies, it dotibtless begins to feed again and once 

 more passes into the matie state in preparation for the 

 next breeding season. But the nature of this process of 

 recuperation has yet to be investigated. 



When they have reached the matie stage, the her- 

 rings, which are at all times gregarious, associate 

 together in conspicuous assemblages, which are called 

 shoals. These are sometimes of prodigious extent— 

 indeed eight or nine miles in length, two or three in 

 breadth, with an unknown depth, are dimensions which 

 are credibly asserted to be sometimes attained. In these 

 shoals the fish are closely packed, like a flock of sheep 

 straying slowlv along a pasture, and it is probably quite 

 safe to assum'e that there is at least one fish for every 

 cubic foot of water occupied by the shoal. If this be so, 

 every square mile of such a shoal, supposing it to be 

 three fathoms deep, must contain more than 500,000,000 

 herrings. And when it is considered that many shoals 

 approach the coasts, not only of our own islands, but 

 of Scandinavia and the Baltic, and of Eastern North 

 America, every spring and autumn, the sum total of the 

 herrings which people our seas surpasses imagination. 



If you read any old and some new books on the 

 natural history of the herring, you will find a wonderlul 

 story about the movements of these shoals. How 

 they start from their home in the Polar Seas, and 

 march south as a great armada which splits into tmnor 

 divisions— one destined to spawn on the Scandi- 



' "Halecum intestina, non modo muha gaudere obesitate, sed et totum 

 corpus eo adeo esse impletum ut aliquando, cum d.sc.ndilur pmguedo ex 

 cultro defluat, et prsesertim eo quidem tempore ubi halecum lactes aut on a 

 crescere primum incipiunt, unde nostrales eos Maalgens- Harnigcii d.cere 

 sclent "— \ V. Leeuwenhoek. "Arcana Nature. Ep. .-icvir (1696). 



Lee'mvenhoek also mentions having heard of "gut pock herrings from 

 Scotch fishermen. 



