34 MARINE AND FISHERIES 



5 GEORGE v., A. 1915 



Figure 4, b drawn from a fresh preparation of the creamy mass in the air 

 bladder shows the arrangement of the oval spores in tetrads. In this the tetrad 

 is inclosed in what may have been one of the cells of the air bladder. 



In fresh preparations the spores measure 16 /i in length by 12 ^ in width. 

 A spore stained with Delafield's haematoxylin is drawn in Figure 4, a. The two 

 sporozoites are seen filling the spore. Each has a nucleus situated near one end. 

 The nucleus of a sporozoite is usually, though not always, situated at one end and 

 the nuclei of the two sporozoites in a spore are usually at opposite ends of the spore. 

 There is no residual protoplasm in the spore. 



The shell of the spore is ellipsoidal. The line of suture of the two valves 

 aoes not lie in a focal plane of the ellipsoid but is shaped so as to give each valve 

 domewhat the form of a spoon. In fresh preparations the spore shell could be 

 deen to consist of two layers, an outer yellowish layer and an inner dark green 

 layer. Figure 4, c drawn from a preparation preserved in Hermann's fluid shows 

 the shape of the valves of the spore shell. 



From the above description there can be no doubt that the organism we are 

 concerned with belongs to the order Coccidiida. Following the classification of 

 Labbe ('99) since the number of archispores (sporoblasts) is limited to four we 

 have: — 



Order Coccidiida 

 Sub-order Oligoplastina 

 Tribe Tetrasporea, 

 and since the spores are oval and bivalve the parasite is to be placed in the genus 

 Goussia, Labbe ('96). Fiebiger ('08) has described under the name of Goussia 

 gadi a species of Goussia infecting the air-bladder of Gadus morrhu and Gadus 

 virens and has identified it with the parasite found by J. Miiller in the air-bladder 

 of Gadus callarias. Auerbach ('09, p. 74, 81) has also described briefly a parasite 

 from the air-bladder of Gadus aeglefinus which he identifies as a species of 

 Goussia. The writer is of opinion that in the present stage of our knowledge 

 these parasites are to be regarded as all belonging to the same species and that 

 the parasite found by him is probably also of this species. 



The microscopic appearance of the diseased air bladder as described by these 

 authors is the same as that found by the writer. The chief difference between 

 the parasites described by Fiebiger and he are in the size of the spores and the 

 form of the sporozoites. The spores of the parasite described by Fiebiger measure 

 only 11 fxX 7 '5 fi as against the 16/li X 12/tof those found by the writer. In 

 describing the sporozoites Fiebiger ('08) says "Es sind dies schlanke Gebilde mit 

 einem vorderen zugespizten und einem hinteren abgerundeten Ende von 10/i Lange 

 und 4 fi Breite." Those found by the writer are proportionately shorter and 

 wider. As these characters are usually considered to be of great systematic im- 

 portance considerable doubt may be expressed as to the two parasites being of 

 the same species. However, the writer considers that other similiarities make 

 it possible that the variations in size may be due to the different environments 

 of the hosts and the difference in the form of the sporozoites, to his not having seen 



