487 



over highly probable that the calyx, which constitutes a universal 

 feature in the ordinary hippocrepian genera, enters here into the 

 composition of the peculiar cup which surrounds the base of the 

 tentacula, and which the author believes has its homology in a per- 

 manently inverted portion of the endocyst, united externally to the 

 uninverted endocyst, and internally to the calyx and tentacula. 



2. On a Case of Lateral Refraction in the Island of Teneriffe. 

 By Professor C. Piazzi Smyth. 



In his astronomical visit to Teneriffe last summer, the author was 

 instructed to inquire into the lateral oscillation of stars, as seen by 

 Baron Von Humboldt in his ascent of the mountain. During a 

 month's residence on the place of the alleged observation no ap- 

 proach to anything of the sort was ever noticed, although a powerful 

 equatorial, with a twelve-foot telescope and high magnifying powers, 

 was employed to detect any irregularity in the motions of the stars. 

 The author concluded, therefore, that the anomalous movements de- 

 scribed by Humboldt could not have been produced by any general 

 or cosmical action of the atmosphere, or of light or heat, which as- 

 tronomers were bound to consider. 



3. On Insect Vision and Blind Insects. By Andrew 

 Murray, Esq. 



Mr Murray commences with a resum6 of what is known regard- 

 ing the growth of eyes in insects, from the 6rst stage in the larva, 

 when many are without eyes, till their exclusion from the chrysalis, 

 when they usually appear well provided with compound eyes. He re- 

 views the nervous system in different species, and gives some details 

 as to those species which live in dark places, and which have small 

 eyes and a less-developed optic nerve, contrary to what one would at 

 first suppose. The next portion of his paper is devoted to explain- 

 ing his views of the structure of the eye in insects, and its re- 

 lation to the eye in vertebrate animals. Instead of seeking the 

 homologies of the parts of the eye in the vertebrata in each separate 

 eye tubule, or individual part of the compound eye in insects, as has 

 hitherto been done, he compares it with the entire compound 

 eye. Resting on the microscopic researches of Kblliker, H. Miiller 



