ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 561 



Expressions of the Emotions in Pigeons.* — W. Craig publishes a 

 paper, the first of a series, on the expression of the emotions in pigeons, 

 the blond ring-dove being the species chosen for this study. The ex- 

 pression of fear, the alarm note, the " kah," or social call, and the " coo," 

 with its various modifications as song or nest call, are described in 

 detail, and, wherever possible, are illustrated by musical notes. Then 

 follows a sketch of the life-cycle of the bird, and of the first occurrence 

 of the different notes in the young bird, and their development in 

 accordance with the growth of the vocal organs and the development of 

 the nervous system. 



Brain of American Alligator.t — A. M. Reese continues his re- 

 searches on the development of the brain of the American alligator, and 

 gives an account of the paraphysis and hypophysis, based on material 

 collected by him in Central America. His results are as follows : The 

 paraphysis in the alligator has long been mistaken for the epiphysis, 

 which latter structure is entirely absent. The paraphysis is first seen in 

 embryos of 7 mm. in length, as a wide evagination of the roof of the 

 forebrain, to the anterior end of the transverse velum. This evagination 

 early becomes partially constricted off from the brain, and forms a 

 rounded, hollow mass connected by a wide stalk with the diencephalon. 

 As growth proceeds, the paraphysis becomes elongated, until, in embryos 

 of 7 cm. in length, it is seen as a tubular structure, with nearly smooth 

 walls slightly curved away from the cerebral hemispheres and over the 

 top of the diencephalon. In embryos of 13 cm. the paraphysis has 

 practically the same structure as the 7 cm. embryo. The velum grows 

 forward into each lateral ventricle to form its choroid plexus. 



The hypophysis in the alligator begins, at about the same stage as 

 the paraphysis, as a single median evagination of the roof of the mouth, 

 just beneath the floor of the infundibulum. The original evagination 

 becomes the stalk of a considerably branched, hollow structure, which, 

 by the lengthening of the stalk, recedes to some distance from the roof 

 of the mouth. The stalk becomes solid, and finally loses all connexion 

 with the oral epithelium. The body of the hypophysis also becomes 

 almost completely solid in an embryo of 13 cm., and is seen as a 

 lobulated mass of lymphoid tissue lying close under the floor of the 

 infundibulum. 



Digestion in Marine Invertebrates.} — H. E. Roaf has made ex- 

 periments to investigate the presence of acid or alkali, during digestion, 

 in the intestine of marine Invertebrates. He has also made some 

 observations on the habits of the animals studied. 



In Actinoloba dicmthus the reaction of the tentacles is practically 

 neutral. The mesenteric filaments show a more acid condition. A 

 case of partial fission was studied, and it was found that the two in- 

 dividuals, although structurally united, were physiologically independent. 



The food of sea-urchins near Port Erin is chiefly composed of 

 barnacles, but seaweed is also found in the intestine. During feeding 

 the pedicellarise, spines, and tube-feet all participate in conveying food 



* Joum. Cornp. Neurol, and Psychol., xix. (1909) pp. 29-80. 



+ Smithsonian Misc. Coll., liv. No. 1922 (1910) pp. 1-20 (5 pis.). 



: Joum. Physiol., xxxix. (1910) pp. 438-52. 



