Scientific Proceedings. 



(hi) 47 



Conclusions. — Trypanosomes from the frog may be cultivated 

 on blood-agar, but, in the authors' experience, with considerable 

 difficulty. 



From a frog infected with Tr. rotatorium a flagellate organism 

 was cultivated, showing important points of difference from Tr. 

 rotatorium. It is possible that, owing to the technical difficulties 

 of the experiment, some other organism may have found its way 

 into the tubes. This is improbable. 



Undoubted trypanosomes developed in blood-agar prepared 

 from a frog whose blood, during life, showed no trypanosomes. 

 They resembled Tr. rotatorium, but were usually much smaller. 

 As this blood- culture medium was inoculated with blood from 

 another source containing Drepanidium, it nearly led to the con- 

 clusion that Trypanosoma might develop from Drepanidium. We 

 have here an illustration of the ease with which mistakes may 

 occur in the cultivation of hematozoa which are suspected of pass- 

 ing through cycles. Such a possibility had been pointed out in 

 advance by Novy and MacNeal before this society [page 23 (87)]. 



There was no evidence from the experiments to show that 

 development of Drepanidium can occur on blood-agar. 



It is unlikely that material with which further studies may be 

 made can be secured before next summer (1905). As trypano- 

 somes are now exciting so much interest, and are being so widely 

 studied, the authors deemed it best to report their results at this 

 time, although the work is incomplete. 



19 (65). " Experimental measles " : LUDVIG HEKTOEN. (Pre- 

 sented by EUGENE L. QPXE.) 



The search for the cause of an infectious disease like measles be- 

 comes greatly simplified when we learn how to secure the unknown 

 " virus" in relatively pure form unmixed with common microbes. 

 Various methods may now be applied to the investigation of the 

 virus. The transmission of measles from mother to fetus would 

 seem to point to the presence of the cause of the disease in the 

 blood. In the twenty cases of fetal measles collected by Ballan- 

 tyne, it seemed that the infection of mother and fetus must have 

 been simultaneous, because the eruption in both corresponded in 

 character. In order to learn something further as to the presence 



