( 347 ) 

 The accompanying drawing represents the seed and its ap- 

 pendages, more or less magnified. 



Explanation of the Figures in Plate I. 



Fig . 6. The two valves of the glumaceous perianth, widi the stiff hairs, 

 the spine and articulated awn. 



7. The grain, with part of the skin torn at the base, to shew the 

 albumen, of which nearly the whole is composed, the cotyledon 

 and the embryo. 



8. The seed, with a fourth part of the awn, to shew its form when 

 ready to separate from the spike* 



9. The same, as it appeals some hours after separation. 



Account of the Observations and Experiments made on the 

 Diurnal Variation and Intensity of' the Magnetic Needle, by 

 Captain Parry, Lieutenant Foster, and Lieutenant Ross, in 

 Captain Parry'' s Third Voyage, with Remarks and Illustra- 

 tions. By Peter Barlow, F. R. S. Mem. of the Imperial 

 Academy of St Petersburgh, &c. (With a Plate.) Com- 

 municated by the Author. 



J\.S the experiments referred to in the head of this article were 

 performed under such extraordinary advantages of locality, of 



at the base in a reversed cone, which is very sharp, and covered with stiff hairs 

 directed upwards, so that when the point penetrates into any substance, the 

 hairs not only prevent it from coming out, but contribute to make it go 

 deeper. M. Desfontaines, in his Flora Atlantica, and M. Lamarck in the Ency- 

 clopedie, have pointed out the inconveniences to which a seed so organised sub- 

 jects travellers passing over the fields of Barbary, Greece, and Portugal, at 

 the time of ripening of the stipas. The seed penetrates into their clothes, 

 and sooner or latter disconveniences them in a high degree, by produc- 

 ing scratches of various depths upon the skin. A great mortality of the 

 cattle, which took place in 1823, in the neighbourhood of the village of 

 Berczel in Hungary, afforded an opportunity to the Professors of the 

 lloyal University of Pesth, of making known a still more singular effect pro- 

 duced by these seeds. It was found that the seeds of the stipas, which abound 

 in the pasture grounds of Berczel, stuck to the wool of the sheep, penetrated 

 into the skin, and even made their way to the internal organs. On dissecting 

 a great number of these sheep, seeds were found in the vicinity of the liver 

 and in the peritonaeum, and the skin, examined between the eye and the light, 

 had the appearance of a sort of riddle. As these grasses occur in all the south- 



