TRANSACTIONS OF SECTION D. 1103 
embryonic condition persists throughout life. In Megascolea and Microcheta the 
anterior section of the dorsal vessel is double, the two vessels fusing together 
where they traverse the mesenterics. In Acanthodrilus novezelandie the dorsal 
vessel is double throughout the whole body, the two tubes becoming fused as 
in Megascolex at the mesenterics. In A. muléiporus the primitive condition is more 
completely retained, since there are two dorsal vessels which remain distinct as far 
as the anterior extremity, and do not fuse where they traverse the mesenterics, 
5. On the Cervical Vertebree in Balena mysticetus, Sc. 
By Professor Strutuers, M.D., LL.D. 
Hight specimens of Mysticetus showed the bodies completely consolidated, evem 
in the young state, with external indications. In some the first dorsal also united. 
Superior and inferior transverse processes slender and partially united externally. 
From his dissections of the soft parts in the Finners, the author could recognise the 
three stages of these transverse processes, the nerve-groove stage internally on the 
superior processes, externally on the inferior. The pedicles are much and variously 
atrophied. 
Numerous specimens of Globicephalus showed the stages of consolidation. The 
rudimentary bodies, though very thin, have their epiphyses. In the young the line 
between the atlas and axis is distinct. In a young specimen the change of position 
of the transverse processes in relation to the neuro-central suture between the 
8th and 10th dorsal vertebrze is well seen. 
Dissections of Beluga and Monodon (Narwhal) showed the deficient bony trans- 
verse processes to he fully represented by fibrous cords and bands completing the 
rings, 
6. On the Development of the Foot of the Horse. 
By Professor Strutuers, M.D., LL.D. 
Attention is called to the fact that the epiphysis of the rudimentary metacarpal 
and metatarsal bones is not situated at the upper or functional end, but, as in the 
case of the great metacarpal and metatarsal, at the lower end, here rudimentary. 
From this a ligament proceeds, expanding in a fascia. The position of this epiphysis 
is a significant fact, as a link in the chain of evidence of the descent of the horse. 
It had its use here in the hipparion and other forms which preceded the horse ot 
the present day. The sections of the feet of young horses exhibited by the author 
also showed that the pastern bone, or first phalanx, has an epiphysis at the distal as 
well as at the proximal end, the distal epiphysis consolidating early. In the course 
of this paper, the author showed a specimen of polydactyly in the horse, the 
additional toe about one third the size of the main toe. 
7. On the Development of the Vertebree of the Elephant. 
By Professor Srxuruers, M.D., LL.D. 
On the anterior vertebrze the neural arches meet below so as to shut out the 
bodies from forming any part of the spinal canal. The bodies are buried an inch 
deep by this mesial meeting of the neurapophyses. This diminishes backwards, 
the bodies at length rising to form part of the wall of the spinal canal. The 
“verteébre exhibited were from an elephant, said by the keeper to have been about 
thirty years of age. 
8. On the Kidneys of Gasteropoda and the Renal duct of Paludina. 
By W.B, Brennan. 
