422 Royal Society :--^ 



7th. The oscula or excurrent orifices, usually permanent organs, 

 and capable of being opened or closed in accordance with the neces- 

 sities of the animal. 



8th. Inhalation and exhalation. Two modes of these operations 

 are described ; one as occasional or intermittent, but very powerful, 

 for the imbibition of nutriment ; the other gentle and continuous, for 

 the purposes of the aeration of the vital fluids, and for the ejection 

 of digested matters. 



9th. Nutrition. The modes of imbibition and periods of digestion 

 are treated of; and the author describes a series of contrivances by 

 which some sponges are in possession of peculiar organs which en- 

 able them to prey upon annelids or other soft creatures that may 

 crawl over their surface or intrude within their cavities or canals. 



10th, Cilia and ciliary action. The accounts of the cilia of the 

 gemmules or ova, as described by Dr. Grant and other writers, are 

 referred to by the author ; and the same organs in situ in Grantia 

 compressa are pointed out as the powers on which inhalation and ex- 

 halation are dependent. 



11th. Reproduction, gemmules, &c. Under this head the ovaries, 

 ova, and gemmular modes of propagation are described under five 

 heads : — 



1st. Ova without an ovarium. 



2nd. Ova generated within ovaria. 



3rd, Gemmules secreted within the sponge. 



4th. Gemmules produced externally. 



5th. By spontaneous division of the sarcode. 



The remaining portions of the paper, consisting of observations on 

 the generic characters, the specific characters, and on the mode 

 of examination, will form the subject of a future communication. 



"Observations on the Posterior Lobes of the Cerebrum of the 

 Quadrumana, with a Description of the Brain of a Galago" by 

 William H. Flower, Esq., Demonstrator of Anatomy at the Middlesex 

 Hospital. 



After referring to the present state of our knowledge upon the 

 subject, and especially to the descriptions recently given of the 

 "posterior cornu of the lateral ventricle" and "hippocampus 

 minor" in the Orang-Utang by Dr. RoUeston, in the Chimpanzee 

 by Mr. Marshall, and in Ateles by Mr. Huxley, and the statement 

 of M. Gratiolet, that the posterior cornu of the lateral ventricle or 

 " cavite ancyro'ide" obtains an enormous development in Monkeys, 

 the author proceeds to detail his own observations (which are illus- 

 trated by drawings and photographic representations) upon the con- 

 dition of these parts in the brains of animals belonging to the three 

 famiUes of the order Quadrumana. 



Family 1. Catarrhina. 

 Oranff'Uianff (Pithecus satyrus). — An account is given of the 



