78
Para. 42
perhaps the most important diseases in the country. I venture to recommend
that instruction in these matters should not only be theoretical, but should
extend to the practical detection of the parasites by the microscope; and can
vouch for it from personal knowledge that native subordinates are quite capable
of doing the work if taught how to do it.
A more general use of the microscope, especially for the detection of
intestinal parasites, is, I am confident, very urgently demanded in tropical
medicine.
I have not made these last recommendations lightly; carrying them
out will involve some expense to Government and some trouble to medical
officers; but it is difficult to escape from the fact that until they are carried
out patients will have just cause to complain that they are not being treated by
the best methods.
CONCLUSION.
The great length of this report is due to the necessity which has arisen for
investigating and discussing the amphibolic febris secondaria, and the condi-
tion of unpigmented enlargement of the organs found in kala-azar. I trust,
however, that the attention here drawn to these apparent anomalies will be of
some general use in tropical medicine.
Owing partly to the labour involved in this work and partly to the plague
scare in Bengal having greatly enhanced the difficulties of carrying out experi-
ments with human malaria, I have failed in repeating my original cultivations
of the human parasites in mosquitoes, although many attempts with dappled
winged and other insects have been made. Fortunately, however, I am able to
conclude this report with the statement that Grassi, Bignami, and Bastianelli
have been more lucky in Italy. Some of my preparations of proteosoma in the
mosquito, together with copies of my reports on the subject, were sent to these
observers last autumn; and they at once essayed the cultivation of the human
parasites according to the methods enjoined by Dr. Manson and employed by
me. They were immediately successful; and found that both theæstivo-
auturnnal and mild tertian parasites are cultivable in an Italian species of
dappled-winged mosquito, the Anopheles claviger or maculipennis. Their results
are published in a paper [41], dated the 22nd December 1898. As anticipated
by me, the former parasite produces germinal threads which, like those of pro-
teosoma, enter the veneno-salivary gland of the insect. Hence the last possible
doubt as to the comrnunicability of human malaria has been removed.
Black spores have also been observed in the mosquito stage of the human
parasites; but some recent observations of mine tend toward throwing doubt on
the exact nature of these bodies.
My thanks are due to Captain McNaught, Dr. Lavertine, Dr. Dodds Price,
and Major Macnamara for their valuable statements; and also to Dr. Daniels
for his assistance in regard to the sections, and especially for his having been
so kind as to place at my disposal the results of his numerous autopsies-results
which have so important a bearing on the difficulties met with in kala-azar.
I must also express my indebtedness to Colonel Calthrop, Principal
Medical Officer, Assam, for the services of a medical subordinate ; and to W. J.
Reid, Esq., I.C.S., lately Deputy Commissioner, Nowgong, for assistance ren-
dered in many ways.
EONALD ROSS, D.PH., M.R.C.S.,
CALCUTTA ;                             MAJOR, INDIAN MEDICAL SERVICE,
The 30th January 1899.                                                       On Special Duty.