and the specimens taken from infected cattle varied from J inch 
to I inch in length. (See Plate I. G and H.) It infests in cattle 
the liver, gall-bladder, bile-ducts, and has been found in the lungs. 
Tlie life history of the common liver-fluke: — (See Plate I.) 
The' life-history of the fluke is a very complicated affair, occupy- 
ing from 10 to 12 weeks. A brief statement of the important 
phases is sufficient for the purposes of this paper. The eggs (see 
Plate I. A and B) of an adult fluke, numbering from 37,000 to 
45,000, pass from the liver of the infested stock, through the bile- 
ducts to the stomach and then to the intestine, from which they 
are expelled with the faecal matter and, to further develop, must 
fall or be washed into water. In water, and water only, there 
develops within the Qgg a ciliated embryo which finally bursts 
through the eggshell and swims actively about. To further de- 
velop this organism must find or come in contact with certain 
fresh-water snails. Two species of these intermediate hosts are 
recorded from these Islands, Limnaea oahuensis (see Plate I. 
I and J) and Limnaea rubella. The former species occurring on 
Oahu and Maui and the latter on Oahu and Kauai.* 
It is probable that one or both species are generally distributed 
over the Islands, but if certain districts are free from these species 
the stockmen of those districts have certainly reason for self-con- 
gratulation, since because of their part in the transmission of the 
liver-fluke disease, their presence is equally as dangerous to the 
interests of the ranchers as the presence of the fluke itself. To 
continue with the life-history, — these swimming ciliated embryos 
(miracidiitm), (see Plate I, C, ) minute in size, bore their way 
into the body of the snail, if fortunate enough to find a host, and 
seek lodgment in the liver or other parts of the body. Here 
another change in the life-cycle occurs. The organism becomes 
quiet and forms what is known as a sporocyst. (See Plate I, D.) In 
this inactive state each sporocyst gives rise to from 5 to 8 organisms 
within itself called rcdiac. These rediae may be considered a sec- 
ond generation of the immature liver-fluke which leave the spor- 
ocyst when fully developed and seek the liver of the snail, if not 
already lodged there. Within the liver of the snail there is still 
another multiplication of individuals, that is, each redia (see 
Plate I. E.) gives rise to from 12 to 20 further organisms known 
* Fauna Hawaiiensis. Vol. II. Part IV, pp. 392, 393. 
