Altogether, then, this part of the inquiry is very perplexing. Other parts are definite enough. All the poisons, for instance, yield very definite results, which are in conformity with their actions elsewhere. I have had no time to do anything at the histology as yet. Would it be worth while for me to send you various species in a little sea water? They would arrive in a tolerably fresh condition, but would require to be examined at once. I might try sending some in spirit and others in chromic acid. I have made a few preliminary experiments with the galvanometer on Sarsia, placing one electrode on the margin and another on the muscular sheet, but without any decided results. I also tried placing a Sarsia in one beaker and simple sea water in another, connecting by means of the electrodes, but no disturbance was observable. June 4. I am working very hard just now, as there are so many irons to keep hot at once. It is too soon yet to see the results of spring grafting on the many plants I have operated on, and I have not had time to do anything with animals since I left London. The Medusæ have now come on in their legion, and occupy my undivided attention. The results so far have proved as definite as they are interesting and important. The following is a summary of the principal. All genera of naked-eyed yet examined become immediately and permanently paralysed (except polypite) upon excision of margin, but not so with the covered-eyed. The organism thus mutilated responds with a single contraction to a nip with the forceps, also to various chemical stimuli. The chain of ganglia do the same, and further resemble the mutilated organism in contracting once to both make and break of direct or of induced shock. They differ, however, in one important particular: the severed margin retains its sensibility to the induced shock much longer than to the direct, while with the necto-calyx the converse is the case--the latter responding vigorously to make and break of direct current after it has ceased to be affected by even interrupted current with secondary coil pushed up to zero (one cell).