354 Messrs. R. G. Nelson and P. M. Duncan on the 



for twenty-four hours at a temperature of 35°-40° C. ( = 95°- 

 104° F.) in a solution of one half per cent, of phosphate of 

 soda and ammonia. At a lower temperature it takes longer 

 tinder otherwise similar conditions before this phenomenon ia 

 manifested. Thus it requires four days at about 15°C.( =59°F.) 

 and three weeks at 6° C. ( = 42°'8 F.). At 0°-5° C. (=32°- 

 41° F.) we see the Vibrtones &c., which then move less briskly 

 and not so generally, grow in from fovir to six weeks from the 

 albuminous simple germ-cells into the cylindi-ico-filiform and 

 the various other above-mentioned forms of amyloid hy&tero- 

 phymata. 



As has already been stated, the germs diffused and freely 

 floating in the nutritive fluid are always developed earlier than 

 those enclosed in the cells, as also usually are those contained 

 in the intercellular spaces (see ^Chemismus' &c. p. 35), just 

 as in general the development of the germs between the 

 superimposed membranes of a tissue-cell system advances 

 from without inwards, and this not only in vegetable but also 

 in animal cells, e. g. in those of cartilage. 



During this development of amyloid hysterophymata the 

 nutritive fluid very soon becomes acid by the formation of 

 lactic and butj^ric acids. 



Under these conditions, at the above temperature there com- 

 mences a retrogression of the amyloid bodies ; the younger 

 cell- vegetations originating in their joint-cells absorb the 

 amyloid without forming fresh, and become developed into 

 smaU DicQcci and 5ac^er?a, which are rendered yellow by iodine. 



The production of the organic acids promotes the develop- 

 ment of the Vibrio joint-cells into yeast ; an addition of sugar 

 to the fluid containing amyloid hysterophymata, even when it 

 is boiled for hours and with the greatest care, hastens this 

 development of yeast ; so also an addition of dilute phosphoric 

 acid, in which even fresh vegetable tissue develops yeast instead 

 of Vibrtones. 



ScbafHiausen, February 1876. 



XXXVII. — On the Actinozoan Nature o/Millepora alcicornis, 

 Dana and Linn. [pars). By R. G. Nelson, Major-General 

 E.E., and P. Martin Duncan, F.R.S. &c. 



Every one who has examined the hard parts of a Millepore 

 critically is impressed with the existence of calices, limited 

 beneath by tabulae, and separated by more or less spongy-^ 

 looking coenenchyma consisting of reticulate and excessively 



