SOME OBSERVATIONS ON A NEW OKEGARINE. 263 



By the kindness of Professor Sedgwick, who allowed me a 

 free hand in the laboratory of the Imperial College of Science, 

 S. Kensington, I was able eventually to complete my study of 

 the sections. And in this connection I must express my 

 indebtedness to Mr. C. C. Dobell, who is at present lecturing 

 at the College. His unrivalled knowledge of protozoan life- 

 history and technique has always been most generously 

 placed at my disposal, and has proved of the greatest value in 

 the preparation of this paper. 



Material and Methods, 



The leech which serves as host to Metamera schubergi 

 is Glossosiphonia complanata Linn. A few specimens 

 of Hemiclepsis marginata were also found infected. The 

 leeches live under stones in shallow water — running by pi'e- 

 ference — though I have found them in smaller numbers in still 

 pools. The material was collected at Heidelberg from the 

 shallows left by the summer fall of the Neckar in tlie neigh- 

 bourhood of the electric power station, below the new bridge, 

 and also from the opposite bank, aloug the wall separating 

 the skating rink from the liver itseU'. The leeches are fairly 

 common, and may be found clinging firmly to the under-side 

 of stones at the water's edge, especially in the numerous lumps 

 of red sandstone which litter the shore everywhere. 



Recently I examined some specimens of Glossosiphonia 

 complanata sent me from the neighbourhood of Cambridge, 

 and found them well infected.^ These latter were obtained 

 in January, when the leeches are hard to find owing to the 

 scanty vegetation in the ponds in winter. In all the speci- 

 mens I examined from this source I only obtained one cyst, 

 and that a very small and early one. 



The leeches can be kept for an indefinite period in a good- 

 sized glass jar, provided the water be aerated by passing 

 bubbles of air through it. Food is not necessary, though a 



^ For this I have to thank Mr. Harding, and also for Lis kindness in 

 assisting me to determine the species. 



