334 



NATURE 



IJuly 25. 1878 



and to which I have applied the term "specific genesis," 

 and it is this which I am more and more persuaded is the 

 determining agent in, and therefore the one true cause of, 

 the origin of species. 



St. George Mivart 



VARYING EXPERIENCES 



I LOVE to repeat other people's experiments, and 

 though not in the least doubting the accuracy of 

 recorded observations in relation to bees, clover blossoms, 

 and fertilisation, some years ago I covered patches with 

 wire netting, to exclude the bees, for all, every flower I 

 believe, perfected its seeds. I hope I have earned a 

 reputation for accuracy in my statements of facts, and 

 that it is not necessary for me to call witnesses. I will 

 say here, however, that about that time I was visited by 

 Dr. Sterry Hunt, ex-President of the American Associa- 

 tion for the Advancement of Science, and together we 

 uncovered one patch, and examined a few mature heads, 

 with the result as above stated. 



Recently I referred to Mr. Darwin's statement that one 

 might as well sprinkle Litium perenne with so much 

 inorganic dust as its own pollen, and stated that in my 

 own garden a plant from the Rocky Mountains perfects 

 seeds, and can only use its own pollen. An esteemed 

 friend takes me to task ' for this statement, remarking 

 that I have overlooked that Mr. Darwin's facts are con- 

 firmed by Dr. Fritz Miiller, in Brazil. This, in connection 

 with remarks made on my clover experience, leads me to 

 suppose that some believe I have offered the facts in 

 opposition to those of Mr. Darwin. Nothing has been 

 further from my thoughts. My point has been to show 

 that plants or insects do not always behave in the 

 same manner, on all occasions, and under all circum- 

 stances. I had an interesting illustration of this in 

 March last. Having occasion to examine a large patch 

 of chickweed {Stellaria media), I was surprised to find a 

 number of honey-bees engaged in collecting pollen from 

 them. For the past few years I have made a point of 

 closely watching the behaviour of insects towards flowers, 

 and I never saw honey-bees at work on chickweed before ; 

 I never heard of any one who has. I believe the chick- 

 weed has been given up to rigid self-fertilisation. Pro- 

 fusely among the chickweed grew Draba verna. The 

 flowers of the two are about the same size, and both 

 white, but the bees kept with strict exclusiveness to the 

 chickweed. Yet I know that the Draba is not obnoxious 

 to them, for in other years I have seen them at work on 

 these flowers. Among them also were some Capsella 

 Bursa-pastoris in bloom ; but they also were passed by. 

 I have never seen bees or any insects on the shepherd's 

 purse, but from this chickweed experience it would not 

 be safe to say none ever do visit them. The date of this 

 visit of the bees was March 15, the thermometer 52°, 

 spring scarcely begun, and only these three ear!y plants 

 in bloom. 



I had a similar instance last autumn of the honey-bee's 

 faith in the crust of bread theory rather than have no loaf 

 at all. We had an open mild season, and towards 

 Christmas, long after all other flowers were gone, the 

 Salvia spkndais, of which I employed a large number in 

 the decoration of my grounds, was alone in flower. On 

 warm days they were thronged with honey-bees, and I 

 feel almost sure they had never visited my plants in other 

 years when other flowers were to be had. The corolla 

 tube is too long for the bees, so they had to bore the 

 corolla from the outside. Boring from the outside is easy 

 work for our large humble-bees. Almost all our flowers 

 which off"er the least obstruction to mouth entrarce are 

 robbed of their sweets in this manner. Even red clover 

 is " tapped " by them in this way. But it was very hard 



• In Sillhnan's youmal. 



work for the honey-bees, and I am sure that, only for the 

 absence of other and easier worked flowers, I should not 

 yet be able to say that I had seen the honey-bee bore 

 from the outside of a flower, as the humble-bee generally 

 does. There were white-flowered varieties of this species 

 among the scarlet ones, but all were treated alike. 



It seems to me that bees are not attracted to flowers 

 by colour or fragrance merely, but that they are influenced 

 by labour-saving ideas. A little experience teaches them 

 how best to work in any species to advantage, and they 

 will of course " make time " by keeping to this one till all 

 are done. White varieties or scarlet varieties are all one 

 to them, they can distinguish the species by other means 

 than colour. And then they learn where to work to the 

 best advantage, and only glean in poor fields after the 

 richer harvest has been gathered. These considerations 

 will naturally lead to different behaviour in different 

 climates, and if I note these differences it is very far from 

 my intention to offer them as contradicting the experiences 

 of others ; on the contrary, no one has a higher apprecia- 

 tion of their value. Thomas Meehan 



Germantown, U.S. 



OVR ASTRONOMICAL COLUMN 



Double Stars. — In Gilliss's catalogue of 290 double 

 stars formed from observations made at Santiago, Chile, 

 during the U.S. Astronomical Expedition in the years 

 1850-52, the conspicuous star a Eridani {Achernar), is 

 reported to have been seen double, the companion being 

 of the seventh magnitude, faint blue, and preceding, 3" 

 south. We look in vain for mention of this companion- 

 star in the observations of Herschel, Jacob, and Powell, 

 and it is especially strange that it should not have been 

 detected by the former during his sweeps with the 20-feet 

 reflector at the Cape. The well-known binary p Eridani 

 is less than 2° distant, consisting of two nearly equal com- 

 ponents of between the sixth and seventh magnitude, and 

 at first sight it might be inferred that by a typographical 

 error the name of the star is wrongly given by Gilliss. 

 His position, however, is that of a Eridani, and further 

 we happen to possess measures of p Eridani by Jacob, at 

 the precise epoch of the Santiago observation 185079, 

 giving for the angle 268°7, and distance 4"'32 ; the comes 

 therefore could hardly be described as preceding, 3" south, 

 but might rather be said to precede on the parallel. This 

 would indicate that the star intended is really Achernar, 

 and it must be left for further observation to decide upon 

 the accuracy or otherwise of the statement made by Gilliss. 

 If the companion exists it would be of interest to know its 

 present position ; the proper motion of the principal star is 

 very insignificant, and marked difference from Gilliss's de- 

 scription would be suspiciousasshowingabinary character. 

 Still it is to be observed that there are considerable dis- 

 cordances between the angles and distances of many of 

 the stars in the Santiago catalogue and those in Her- 

 schel's Cape volume. The former are not the results of 

 actual micrometrical measures. It is stated that the 

 catalogue was formed by plotting, on a large scale, th« 

 differences of right ascension and declination of the 

 components of the double-stars observed with the transit ■ 

 circle (4^ inches aperture), and then measuring from the 

 drawings the angles of position and distances. In most 

 cases the right ascensions and declinations observed are 

 given in the preceding catalogue of 1,963 stars, and the re- 

 sults of the graphical process can be verified by calculation. 

 In looking through the list of double-stars the reader will 

 note differences from Herschel' s data, which are not 

 always easily explained by possible motion, though, as 

 some of the stars have not been properly measured since 

 Herschel's epoch, there will remain a doubt as to the 

 cause of these differences. As instances in point, we 

 may mention the following numbers of the Cape cata- 



