744 TRANSACTIONS OF SECTION D. 



Hemidactylus triedri harbours, as well as Tri/panosonia pertenuis, Hcemogregarina 

 triedri{M.\h.i). This form has a double capsule, a loose deeply-staining outer sheath, 

 and a delicate inner capsule with an operculum. 



Among snakes the common rat-snake, Zamenis mucosas &ndChrysoj)elea ornata, 

 both showed the same species of Hfemogregarine — a form with highly refractive 

 capsule thickened at both ends. 



Haemogregarines were also found in the cobra and Python reticulatus. The 

 form in the python is very actively motile in its free phase. 



8. On the Structure of Dendrosonia radians. 

 By Professor Sydney J. Hickson, M.A., F.K.S., and J. T. Wadsworth. 



The bodies described by Kent as the ' exogenously produced germs ' of 

 Dendrosoma are epizoic, or possibly parasitic, Acinetaria belonging to the genus 

 Urnula. The only true reproductive bodies of the species are the so-called 

 'internal buds,' or gemmulcc, first described and correctly figured by Levick. Tbe 

 raeganucleus is a long strap-like body in the axis of the base and branches, but it 

 is in some respects incorrectly drawn in all the figures that have been published. 

 It never, or very rarely, extends as far as the distal extremity of the processes, 

 and some of the shorter branches have no meganucleus in them at all. 



In many specimens the micronuclei can be clearly seen. When they reach 

 their full size they are 4 /i in diameter. In the division of the micronuclei a 

 spindle is formed 24 fi in length. The chromosomes are very numerous and 

 minute. There are no centrosomata. Conjugation has not yet been observed in 

 the genus. 



9. On some Points connected with the Vetebrate Alimentary Canal, more 

 particularly in that of the Higher Mammalia. By Professor 

 Alexander Fraser. 



10. The Maxilla and Palatine in the Mammalia. 

 By Professor Richard John Anderson, M.D., M.A. 



The extent of the palate process and its relation to the horizontal plate of the 

 palatine are the chief points considered. The following table gives the measure- 

 ments of the inter-palatine suture and the inter-maxillary suture. The position 

 of the posterior border of the hard palate has been examined, also the length of 

 the maxilla along the molar line, and in some cases the distance of the summit 

 of the frontal process of the maxilla from the anterior part of the maxilla below 

 and from the tuberosity behind. Taking the two latter and comparing with the 

 molar line, the three are very nearly equal in several cercopithecidse examined. 

 So the first two measurements may be equal and the last different. In the first 

 case the maxilla would be a pyramid on an equilateral base. 



The palatine border varies in position at difierent periods of development. 



The formation of the teeth is responsible for much of the change. The hori- 

 zontal plates of the palatines make up for the altered maxillo-palatine plate. The 

 enlarged back teeth, with the corresponding enlargement of the alveolar process, 

 taken in connection with the extended horizontal palatine plate, are not without 

 significance. It seems that an absorption of lime phosphate from an adjacent 

 portion of bone is the easiest way to obtain this salt for new ossific matter. The 

 thinning or fenestration or vacuolation of a bone might easily serve for this. 

 We find, at all events, extension of the palatines forwards (hystricoidea) — 

 eg., capybara, hystrix, or backwards (ursidse); in some mammals fenestra- 



