236 BULLETIN OF THE BUREAU OF FISHERIES. 



he began putting down more stakes in various places and watched for the result. 

 These also, in turn, became covered with growing colonies of mussels. Continuing 

 his observations, he soon concluded that the young of native mussels could be collected 

 and profitably raised under artificial conditions. The result of his investigations was 

 the establishment of the bouchot system of mussel culture for which France has become 

 famous. 



The bouchot system as finally perfected by Walton consists of rows of stakes 

 arranged in the form of a V, with its apex pointing toward the sea or the direction 

 from which the strong waves and tide come. This arrangement is to protect the 

 structure from the destructive action of the wind, waves, and ice. The stakes are 

 trunks of trees 6 to 12 inches in diameter and from 10 to 15 feet in length. They are 

 placed from 2 to 3 feet apart and driven into the mud for about half their length. 

 Then branches of osier or chestnut are twisted back and forth between the posts in 

 horizontal rows about 20 inches apart from the top to within a foot of the bottom. If 

 placed closer together than this they are apt to accumulate mud and cause deposition 

 of silt. Walton left an opening from 3 to 4 feet wide at the apex of the two wings 

 where traps were placed to catch the fish which went out with the tide, thus making the 

 structure serve a double purpose. 



The length of the wings depends on the size of the area covered by the tide, which 

 is about one-fourth of the distance between the extreme limits of high and low tides. 

 At the present time in the Bay of Aiguillon they are about 250 yards in length but 

 are no longer arranged in the historic V form. According to Herdman (1894) they 

 are now arranged at right angles to the shore in parallel rows about 30 yards apart, as 

 is shown in figure 221, 4. 



The bouchots are arranged in three series, according to the particular function 

 each is to perform. One set consists of large solitary stakes placed about 1 foot apart 

 out in deep water where they are uncovered only by the lowest tides. These serve for 

 the collection of spat and are known as the bouchots d'aval, or low crawls (fig. 221, 2). 



The second series of bouchots is placed halfway between tide marks and serves for 

 the growth and fattening of the mussels. Several rows of crawls, each with a separate 

 name, may enter into this series. The general term applied to this group is the bouchots 

 batards, or false crawls (fig. 221, 3). 



The third series of bouchots is in the upper limits between tide marks where they are 

 exposed several hours each day during low water. These crawls are known as the 

 bouchots d'amont and serve to inure the mussels to exposure and consequently make 

 them keep longer and fresher than those from the lower rows (fig. 153, 4). 



The method of working the bouchots is to collect seed mussels and transfer them 

 successively from the lower to the higher bouchots at the proper times. The spat is 

 liberated in the Bay of Aiguillon during February and March and is caught on the low 

 crawls which are situated in an ideal position for the preservation and growth of the 

 young shellfish, since they are rarely exposed to the air. When such an event does 

 occur it is for a short time only. When the set of spat first appears the young mollusks 

 are smaller than a grain of flaxseed and are called naissan. The young mussels grow 

 rapidly so that by July they reach the size of an ordinary bean. In this condition they 

 are termed renouvelain. They are then ready for transplanting. 



