78 H. MARSHALL WARD. 



cinth root added : the whole was then boiled. A new close fitting 

 cork was fitted and provided with a short bent tube and a long one as 

 for an ordinary wash-bottle, but with the following differences. The 

 long exit tube dipping below into the solution in the test-tube was 

 drawn to a fine capillary end, and the free end of the same tube was 

 drawn out very fine indeed and its end hermetically sealed in a flame. 

 The short tube had the limb which is placed in the mouth constricted 

 in the middle to a narrow capillary, between which and the mouth a 

 plug of cotton wool was fitted. The fused tip was then broken off and 

 the whole was ready for use. On blowing gently down the mouthpiece, 

 the cotton- wool prevents the passage of spores into the liquid, and the 

 fusion of the exit end, after a minute drop of the nutritive fluid has 

 been expelled, effectually prevents spores obtaining access that way. 

 The other advantages are obvious, and the highly putrescible nutri- 

 tive solution can be employed day after day for the supply of minute 

 drops of nutriment to the cultures. While it is not intended to imply 

 that such a vessel is absolutely proof against bacteria, it is certainly 

 useful in preventing their being added in serious quantities, and can 

 easily be quite freed from other spores. 



The next precaution was to sow as few spores of the Myxomycete 

 as possible at a time, and this I accomplished by the well known 

 method of dipping the needle point, on which the spores to be sown 

 adhered, into a drop of pure water, a drop from which was then placed 

 in the culture drop suspended in the damp-cell. Certain other more 

 obvious precautions may be passed over. The result was that in a 

 fair proportion of sowings germination proceeded normally and rapidly, 

 and very few bacteria (and no larger organisms) made their appearance 

 during the earlier stages ; hence the objectionable turbidity was ob- 

 viated, and the struggle for existence was considerably in favour of 

 the Myxomycete. 



A number of experiments were next made in which the nature of the 

 fluid was varied : the following sums up the chief results. Germination 

 takes place normally in pure water (unless the temperature is too low, 

 or other unfavourable conditions prevail), but the myxamoebse rapidly 

 pass over into the dormant condition and encyst. In a purely mineral 

 nutritive solution the same results are obtained. If an infusion of 

 Hyacinth roots is added to the mineral solution, however, the myxa- 

 moebEe most evidently flourish, and I have kept them and their 

 progeny alive for as long as 16 days in such a solution. Bacteria 



