Ifraser] migrations OF MARINE ANIMALS 143 



Sponges have no migratory representatives. In the Protozoa 

 periodic migration, if there is such, would be rather hard to follow. 

 At certain times some species, particularly among the Flagellates, 

 appear in exceedingly great numbers. The most noticeable instance 

 of this was observed on September 21, 1914, when an area in Departure 

 bay as least as great as half a mile square was brownish green at the 

 surface and for at least a couple of feet below the surface due almost 

 entirely to the presence of Noctiluca. On May 13 of the same year 

 the waters of the bay, just near the station, over ah area of perhaps 

 200 yards square, was of a dark wine color on account of the presence 

 of a Dinoflagellate. On July 9, following this a somewhat similar 

 area, although not quite so large, was seen in Porpoise bay near 

 Sechelt. The color was of a brighter red and was due to an entirely 

 different species. On September 10, 1917, an area greater than either 

 of the last two, but not so large as the first, around the wharves and 

 landings in Nanaimo, as well as in Commercial inlet, was so exten- 

 sively filled with a flagellate species that it had the appearance and 

 almost the consistency of pea soup. Smaller areas have been seen at 

 various times. In any one mass, one species predominates and make 

 up almost the whole of the life in that mass, but different species 

 appear in the different masses. As far as observation has gone, 

 therefore, no idea can be obtained as to the regularity of the appear- 

 ance of any one species. 



In practically all the main classes of marine forms represented in 

 the waters along this coast in which the adults are not sessile or very 

 sedentary, examples may be found that indicate a tendency to migrate 

 periodically. The instances given may or may not be typical of the 

 classes, but they are all common species. If as much attention were 

 given to life-history in any of these classes it is at least possible that 

 there would be as much indication of migration as in the fishes. 



