CORBESPONDENCE. 207 



therefore to give the fungus or the disease a new name. The second 

 figure shows the fungus as seen under a power of 1500 diameters, and 

 conveys a very good idea of the structure of the cell-wall of the 

 conidia, and the mode in which these conidia are developed within 

 the cell-wall of the mycelial threads. But I purposely omit entering 

 into any further account of the microscopic history and relationsliip of 

 the fungus, as my object is a practical one. Suffice it, that I have 

 discovered the fungus and figured its main features. 



" I have been unable to detect any dipterous insects — of which I 

 have specimens — in the ' scrapings ' which I have examined ; and it is 

 clear to me that their presence is accidental, and that they are 

 attracted to the skin, in Tokelau ringworm, by the ointments applied 

 to it, and in which they become imbedded. They are not, so far as the 

 microscope enables me to judge, present in the diseased skin until 

 after ointments have been applied. Further, dipterous insects could 

 not, I take it, possibly cause such an eruption as Tokelau ringworm ; 

 and it is impossible to suppose that, in or ujion a skin in which not a 

 trace whatever of their presence exists, the application of a strong 

 parasiticide would cause the rapid development, in the space of three 

 hours, of a host of these dipterous insects from ova supposedly existing 

 in the skin, and undiscoverable by accurate means of detection. I 

 presume it is the fact of the non-discovery of the fungus which led to 

 the supposition that the diptera may be the cause of the disease. But, 

 now that I have demonstrated the presence of the fungus, and having 

 regard to the general features of the eruption in Lafa Tokelau, the 

 aspect of the question of the relationship of the diptera to the disease, 

 in the light of cause and effect, is altogether altered. I have said that, 

 as compared with exaggerated tinea circinata, Tokelau ringworm offers 

 some points of difference. I think these do not refer to essential 

 features of the eruption, but rather to those which are accidental — 

 viz. to the infiltration and the scaliness ; and these differences are to 

 be explained, I think, by the greater luxuriance and amount of fungus 

 present, which necessarily cause a greater degree of inflammation. It 

 is not necessary to suppose that the fungus is a special one ; the 

 differences referred to will be equally accounted for if it shoufd turn 

 out that the parasite is a modification — a more luxuriant form than 

 usual — of the trichophyton." 



COEKESPONDENCE. 



Gundlach's ^ AND Beneche's No. 7. 



To the Editw of the ^Monthly Microscopical Journal.^ 



Denstone College, August 24, 1874. 

 Sir, — "With our brother microscopists and opticians in Germany a 

 favourite method of testing a i-inch objective is to try if it will show 

 the lines on P. nngiilatiim with perfectly straight simlight, using, of 



