ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 565 



Survival after Injury in Toads.* — W. E. Kellicott examined a 

 natural group of Bufo l&ntiginosus americanus Le C. consisting of 434, 

 and found that 22, or 5*07 p.c., showed injuries, such as crushed 

 feet, broken shank, broken shoulder-girdle. That injuries such as these 

 are not very considerable factors in non-survival is indicated by the fact 

 that the average weight of the 22 injured specimens was 38 ■ 5 gr., as 

 compared with 44*8 gr. for the entire colony. In addition to the 

 5 p.c. injured, 16 individuals, or 8 "6* p.c, showed abnormalites, some of 

 which were serious handicaps. It should be added, however, that, on 

 the whole, the conditions of life were not rigorous for this group of 

 toads. Food was more than abundant, means of protection and con- 

 cealment were ready, and natural enemies did not seem to be numerous. 



Mackerel and Sunshine.f — E. J. Allen discusses the factors affect- 

 ing the abundance of mackerel. Gr. E. Bullen has shown that there 

 seems to be for 1903-7 a correlation between the number of mackerel 

 taken and the amount of Copepod plankton. The food of Copepods 

 seems to be large diatoms and Peridinidas. The vegetable plankton is 

 affected mainly by the composition of the sea-water, the temperature, 

 and the amount of light available. No simple relation has been shown 

 between salinity and plankton-production, and the curves showing the 

 temperature of the surface-water during the fishing months in the 

 different years do not suggest any close connection with mackerel 

 catches. But there seems to be a definite connection between the 

 abundance of mackerel and the amount of bright sunshine. 



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Ear of Flying Fish.J — N. D. Tschernoff has studied the ears of 

 Exoco'tus volitans and E. rondeletii, and has found some errors in the 

 account given by Retzius. In all its parts the ear of the adult is 

 well-developed and in proportion. The following are characteristic 

 features : the long and narrow semicircular canals ; a moderately marked 

 apex ; a small ductus endolymphaticus ; a large sacculus, to which the 

 faintly limited lagena is annexed ; the presence of the macula acustica 

 neglecta, and the absence of a canalis reuniens. 



Abnormal Brill. § — Jas. Johnstone describes a brill {Rhombus Isevis) 

 with a partially arrested metamorphosis, manifested in the incomplete 

 translation of the right eye. The fish is coloured on both sides, but on 

 the blind side part of the head is quite unpigmented. 



Inferior Lobes of Torpedo Brain. || — L. Gentes notes that the 

 inferior lobes are direct lateral expansions of the saccus inftmdibuli, 

 and that their cavity, which persists throughout life, is a diverticulum 

 of that of the third ventricle. They form- a sort of transition between 

 the thick wall of the brain and the infundibular gland. 



* Science, xxvii. (1908) pp. S55-7. 



+ Joum. Mar. Biol. Assoc, viii. (1909) pp. 394-406 (5 figs, and 7 tables). 

 t Anat. Anzeig., xxxiv. (1909) pp. 91-4 (3 figs.). 



§ Report Lancashire Sea-fisheries Laboratory, xvii. (1909) pp. 98-100 (2 pis. 

 and 1 fig.). || C.R Soc. Biol. Paris, briv. (1908) pp. 836-8. 



Oct. 20th, 1909 2 Q 



