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nerve-endings. It will be difficult to find an object of study as favourable 

 as the organ of Eimer. 



Leiden, Anatomical Cabinet. 



DESCRIPTION OF THE FIGURES ON THE PLATE. 



All llie figures are drawn fi'om life from preparations made after the method 

 of BiELScHOwsKY-PoLLACK, With a Camera lucida of Abbe. Fig. 1 and 5 are enlarged 

 1200 times, the others 1600 times. Apochromate-oil-immersion. Sections 5 and 6 jw. 



Fig 1, Longitudinal section of the upper part of a column of Eimer of the 

 earth-mole. A rand fibre {rf) and a part of an axial fibre {mf) are seen. The 

 horny layer (stc) above the column of Eimer is distinctly thinner than at both 

 sides of it. 



Fig. 2. Longitudinal section of a flat cell of the upper part of a column of 

 Eimer, with two tactile discs, growing info the same cell. The nellike structure 

 and the curious drawing in of the connecting fibre, is clearly shown. 



Fig. 3. Longitudinal section of the upper part of a column of Eimer, to show 

 the develophig of the tactile discs, and the final atrophying of the nerve-fibre. 



Fig. 4. From a cross-section through the upper part, of a column of Eimer. 

 A nucleus curved in by a tactile disc. 



Fig. 5. Longitudinal section through the peripheral part of a column of Eimer. 

 Three rand-fibres are shown. The tactile discs lie behind the nerve-fibres. The 

 intracellular position of the tactile discs is clearly to be seen. The upper cell, in 

 which lie four tactile discs, is being transformed into a horny cell. The nerve- 

 fibres degenerate. 



Fig. 6. Gross-section through the upper cells of a column of Eimer. In the 

 section of 6 fjt, four cells were to be seen, lying two and two in the same niveau. 



The tactile discs of the rand-fibres all grow centripetally into" the cells, the axial 

 fibre runs between the cells. 



Astronomy. — "j? Lyrae as a double star." By J. Stein, S. J. at 

 Rome. (Communicated by Prof. H. G. van de Sande Bakhuyzen). 



1. As far as I know, Professor E. C. Pickering was the first who, 

 led by his spectroscopic investigations, suggested that /? Lyrae might 

 be a close double, the components of which describe circular orbits 

 in a light-period ^). 



This surmise was confirmed by Belopolsky ') in 1892. He measured 

 the displacement of the luminous i^-line on some fourteen spectographs. 

 They were found to show a minimum (in absolute Aalue) at the 

 time of the minima and a maximum at the time of the maxima of 



1) Spectrum of |3 Lyrae. By Prof Edward G. Pickering. A. N. 3051 (1891). 

 2j Les changements dans le spectre de (3 Lyrae. A. Belopolsky. Memorie delta 

 Societa degli Spettroscopisti Italiani. Vol. XXII, 1893. 



