6 DEPARTMENT OF THE NATAL SERVICE 



examples of five species were obtained, and again on August 2 of one species no less 

 than 7,000,000 frustules were noted (Ch. debile). 



Professor W. A. Clemens' account of the ]Muttoii Fish (Zoarces) is a very 

 thorough study of a species, which is really an excellent fond-fish thoiigh not gener- 

 ally recognized as such. The research was a joint one, in which Mrs. Lucy Smith 

 Clemens collaborated, and 't has much scientific as well as practical value. 



Dr. Huntsman's two valuable reports (seven and eight) embody studies of Plank- 

 ton material collected during Dr. Hjort's fisheries investigations, 1914-15, and treat 

 respectively of the peculiar transparent annelids, the Tomopteridae ; and the floating 

 Tunicates, the Thaliacea ; and demonstrates their varying abundance at different 

 seasons of the year, and the causes of their distribution. 



Dr. Gross's paper. Report IX on the Putrefaction of Fish is of much practical 

 as well as scientific value, and demonstrates vei'y different rates of deterioration as 

 chaTacterizing the various epecies studied. Hence some fish are better adapted for 

 transportation, and for prolonged handling in the mar'kets, than others. This is a 

 new field of investigation and demands more attention owing to its vital importance 

 to fish marketing. Dr. Wilfrid Sadler's report (X) on the causes of " Swelled Canned 

 Sardines " is of similar interest and value. The cause is found to be in the presence 

 of gas-producing bacteria, of which he determined eight varieties, and their source of 

 origin may be due to the intestinal contents of the fish, or to lack of cleanliness in 

 the factory workers, the latter being in the author's opinion the less likely source. 



Professor Philip Cox's list of Cape Breton and Magdalen Islands fishes (XI) 

 collected in 1917, is an interesting addition to our maritime faunistic knowledge, and 

 the synopsis of Canadian Diatoms (XII), by Drs. L. W. Bailey and A. H. MacKay, 

 is a compilation long needed, and embodying extensive researches by the authors. 

 These are reports numbers eleven and twelve. 



Professor J. W. Mavor's paper (XIII) on the utilization of dogfish and other 

 shark-like species, occurring in our Atlantic waters, forms the thirteenth report of the 

 present series, and summarizes all the most important phases of this subject. Now 

 known by the trade-name of " grayfish," they have come into demand in many 

 markets, and it is important to have, in accessible form, information as to the nature 

 and habits of these fish, the character of the flesh, etc., and its chemical composition, 

 especially its food value, palatability, and other points which are of public importance. 

 Dr. Mavor adds some notes on the use of these fish for oil, glue, fertilizer, and other 

 purposes. Dr. Baumann's' report on the analysis of grayfish and Dr. A. B.'Macallum's 

 note on the urea content of the flesh form appendices A and B to the report. 



The fourteenth report of the volume is Dr. McLean Fraser's "Key to the Hydroids 

 of Eastern Canada." illustrated with 109 beautiful figures. It is the first of a proposed 

 series of guides to the marine animals of Canadian waters. These will supply a 

 keenly-felt want amongst all who are interested in the resources of our seas. No 

 handy guides are available for students and the general public which would enable 

 them to recognize and name specimens when obtained. Even scientific workers deplore 

 the lack of such guides and Dr. Eraser's report is a notable beginning. 



The fifteenth report describes a new genus, and three new species of minute fila- 

 mentous Algae of the Order Hormogoneae, by Mr. A. Brooker Klugh, who collected 

 them in the Miramichi river and estuary in 1918, and is preparing a full report on 

 Ihe microscopic flora of the region. 



The last (the sixteenth) report by Dr. A. P. Knight deals with the "Histology 

 of thp Flexor Tendon in the Crushing Claw of the Lobster," with nine figures ,and i? 

 a study of the minute structure of the larger of the two oval keeled plates to which 

 the daw muscles, for opening and closing, are attached. Each plate, which has a 

 laminated structure shows a central core, and network of crossing fibres in the outer 

 portions. These laminae appear, under low powers, to be of two kinds, thirty-two 

 dark coloured in section, and fifty-seven white; but in young lobsters the laminae are 

 fewer. Under a high power, the latter seem to be more uniform, resembling the finest 

 lawn irj appearance. When fresh the texture is soft like cartilage; but hard and brittle 

 after boiling. 



