604 
ZOOLOGICAL LITERATUKE. 
Of the dogs examined 24 per cent, contained Ascaris marginata^ and 
2 „ ,, Dochmius trigonocephalus. 
Of 100 cats 6 contained Tcenia crassicoUis, 
67 „ T. elliptica, 
2 „ Bothriocephalus felix, and 
66 „ Ascmis mystax. 
Thus the 3 principal parasites of the dog are Tcenia mar- 
ginata and cucumerina and Ascaris marginata ; and the mode of 
occurrence of these species, as shown by the author in a tabular 
form (p. 16), leads him to the following conclusions : — The age 
and size of the dog has a marked influence on the occurrence 
of T. marginata^ which is most frequent in large old dogs from 
the suburbs of the city, where the slaughterhouses are situated. 
Ascaris marginata (like Oxyuris vermicularis in the human 
subject) is most abundant in young individuals ; but Tcenia 
cucumerina seems to be developed without reference to the age 
of its host, or to its size and the locality which it inhabits, 
except that all the species are rather more abundant in dogs 
living out of the town than in those from within its limits. The 
number of all, but especially of T. marginata^ is more or less 
reduced in dogs affected with distemper. 
In Iceland the number of dogs attacked by Entozoa is con- 
siderably greater; for whilst of the Danish dogs examined by 
the author 67 per cent, furnished these parasites, the proportion 
in Iceland rises to 93 per cent. In 100 dogs the following 
species occurred : — 
Tcenia marginata 76 times. 
T. ccenurus 18 „ 
T. echinococcus 28 „ 
T. cucumerina 67 „ 
T. canis lagopodis 21 „ 
Bothriocephalus fuscus (see p. 607) . . 6 „ 
Ascaris marginata 2 „ 
Of 31 cats, 25 (or 81 per cent.) had intestinal worms, 
namely : — 
Tm\ia crassicoUis in 7, or 23 per cent. 
T. canis lagopodis in 11, or 36 per cent. 
Ascaris mystax in 16, or 62 per cent. 
With regard to the characters and mode of occurrence of 
these species the author enters into more or less detail {loide 
infra ) . 
In a section on the disease caused by Echinococci in Iceland, 
Krabbe gives an historical account of our knowledge of this 
malady, from the time when it was regarded as a severe he- 
patitis to the detection of its parasitic cause by the researches 
of recent helminthologists, especially Eschricht. According to 
the author the proportion of the people of Iceland aflected by 
