May 23, 1878] 



NATURE 



103 



observations on the frequency of the recurrence of the 

 process of fission, by the continual following of one seg- 

 mental product of the act ; and also from its beginning to 

 its cessation, in a series of separate organisms, making 

 manifest the periods of greatest fissional intensity ; and 

 also showing the result following on the cessation of 

 fission. In the majority of cases it was an exhaustion of 

 vital action and death : but in a certain proportion, in 

 which fission was not so long continued, it was a rapid 

 change to an amoeboid condition, resulting in the 

 absorption or fusing of the lateral flagella with the body, 

 and a change of form ; the organism becoming now quite 

 oval and having only an anterior flagellum. It swims easily, 

 but has lost all the power and freedom of motion pos- 

 sessed before, moving only in a straight line. But it 

 soon comes into contact with a colony of the organism 

 in the springing condition, attaches itself to one of them, 

 which then soon unanchors and both swim away. In 

 the course of time their movements become sluggish ; 

 the sarcode of the bodies is palpably blending, they 

 become quite still, except for amoeboid movements, and 

 then become one mass, oval in form, which elongates 

 into a spindle-shape, remaining motionless and still in all 

 respects for three or four hours ; when, as was ultimately, 

 and by long continued effort made out, it pours out ex- 

 quisitely minute, opaque, apparently round specks, which, 

 when carefully and steadily followed with the best 

 appliances, were seen to develop into the adult form 

 and size. 



The author then desired to discover the relative heat- 

 resisting power of the perfect form, and the germ or 

 spore. The adult forms were proved by a very direct 

 method, which was fully detailed, to be wholly destroyed 

 at a temperature of 142° F. Two methods of heating 

 were employed to test the resistance of the spore. One 

 was the " dry " method which had been employed in the 

 former researches ; but which was somewhat modified 

 and used with special precautions ; and the result of an 

 elaborate series of experiments proved, that by this mode 

 of heating, the spore could resist a temperature of 

 250° F, 



It was next determined to test the heat resistance of 

 the spore when they suffered the heat, diffused in a fluid. 

 The difficulty of accomplishing this, so as to secure an 

 unmistakable result was carefully pointed out and dwelt on ; 

 and the opinion recently expressed by Dr. Bastian that it 

 was " perfectly easy" shown to be an error. 



The apparatus employed for the purpose was specially 

 delicate, but enabled the author to test directly the results 

 of heat on the spores as well as on the adult organism, 

 without exposure after the vessel was once sealed . The 

 form used was specially devised for these observations. 

 The temperatures up to the boiling point of water were 

 got in melted paraffin, and higher temperatures in a 

 digester. The result was that 220° F. was found to be the 

 limit of temperature which the spore of this organism 

 could endure without destruction of vitality. That is to 

 say 30° F. lower than the same spores could bear in a 

 " dry " heat. But it was pointed out, that to endure this 

 temperature, implied protection of some kind : but that 

 this in the nndeveloping germ, was not only capable of 

 being understood, but would doubtless prove of immense 

 value to the organism. 



OUR ASTRONOMICAL COLUMN 



The University Observatory, Oxford. — Prof. 

 Pritchard has published No. i of Astrono7nical Observa- 

 tions made at the University Observatory, Oxford. It 

 comprises observations made between the autumn of 

 1875, when the establishment was first organised, and the 

 end of 1877. They relate to the satellites of Saturn, 

 double stars, and the five comets discovered in 1877, by 



Borrelly, Winnecke, Swift, Coggia, and Tempel, for which 

 provisional elements and, in the case of Winnecke' s 

 comet, an extensive ephemeris are added ; also elements 

 of the orbits of | Ursae Majoris, 70 Ophiuchi, and ^ 

 Bootis, and comparison of the same with the interpola- 

 tion curve drawn according to the method of Sir J. 

 Herschel. The observations of the satellites of Saturn 

 consist of differences of R.A. and N.P.D. from the centre, 

 of the primary, facilitated by the ephemerides which Mr. 

 Marth has regularly supplied; together with the other 

 observations now printed, they have been made with the 

 refractor of I2j-inches aperture, constructed for the 

 observatory by Mr. Howard Grubb, of Dublin, Mr. 

 W. E. Plummer, the first assistant, being credited 

 with the greater part of them. In addition to the above 

 work, it is mentioned that nearly twelve hundred measur- 

 able photographs have been secured by means of Dr. 

 De la Rue's reflector, which he presented to the Obser- 

 vatory, and which is mounted in the eastern dome, and 

 a very beautiful instrument for completing the measure- 

 ment of these photographs has been recently received 

 through the liberality of the same gentleman. The in- 

 stitution is under the control of a Board of Visitors, as 

 usual in so many of the more important astronomical 

 establishments at the present day, the Board being com- 

 posed of the Vice-Chancellor, the Proctors, the Astrono- 

 mer-Royal, the Director of the Cambridge Observatory, 

 the Radcliffe Observer, and four other members elected 

 by the Convocation of the University; these members 

 are at present. Dr. De la Rue, Prof. Bartholomew Price, 

 J. A. Dale, M.A.,''and W. Esson, M.A. 



The position of the University Observatory is in lati- 

 titude 51° 4S' 34"'i5, and longitude 5m. o'4os. west of 

 Greenwich. 



The Cincinnati Observatory. — No. 4 of the pub- 

 lications of this observatory, just issued, contains the 

 results of measures of double stars made in the year 

 1877, with the ii-inch refractor, the object-glass of 

 which was replaced early in the year after having been-, 

 successfully refig^red by Alvan Clark and Sons ; in< 

 addition to this improvement a new driving clock was 

 added. The stars measured are, with very few excep- 

 tions, situate between the equator and 40° of south de- 

 clination, and this selection of objects gives a rather 

 special value to the Cincinnati observations, though it 

 has been notified from Melbourne that the remeasure- 

 ment of Sir John Herschel' s southern stars is in progress 

 there. The methods of observing at Cincinnati, and the 

 investigation of personal equation, are explained in the- 

 introduction, and the larger differences in the measured 

 angles and distances, found on comparison with the 

 catalogues of Struve, Sir John Herschel, Jacob (Poona), 

 and Dembowski's measures of doubles discovered by 

 Mr. Burnham, are indicated. Some of these larger 

 differences occur in the case of well-known rapidly- 

 moving binaries ; but there are others which deserve 

 further attention, to decide upon the cause of the. 

 observed changes. The following may be mentioned : — 



Star. 



k 2036 

 Lalande...24i6 



h 3447 

 Lacaille ...462 



h 3461 

 c Sculptoris ... 



Sir J. Hkrschel's 



Measures. 



Pos. DIst. 



1836-54... 40°4 — 



36-96... — I -82 



1837-11... 75-5 — 



37'5i-- — 3'i2 



1836-54... 69-6 — 



36-70... — S'53 



Cincinnati Measures. 

 Pos. Dist. 



1877-76... 25-1 1-40- 

 1877-80... 90-1 2-20- 



i877"85- 59'o 4-84- 



Of stars observed by Sir J. Herschel with the 20-feet 

 reflector, for Nos. 2,904, 3>494> and 5,113 (which are re- 

 spectively Lacaille 8,262, 702, and 8,098), the Cincinnati 

 measures show differences greater than 20°. The posi- 

 tions of these stars for 1880 are : — 



