QUATREFAGE’S HISTOIRE NATURELLE. 4] 
of our late unfortunate countryman, Dr. Williams, of Swansea, 
who M. de Quatrefages seems to think is regarded by other 
observers as a credible and sound investigator. This we can 
assure him is not the case in England. There is, however, 
one great merit due to Dr. Williams which ought to be univer- 
sally acknowledged, as it is by M. de Quatrefages ; it is that 
of having first “discovered and appreciated those excretory 
ducts to which he applied the name ‘segmental organ.’ 
When we have given credit for ‘this to Dr. Williams, it 1s all 
we can do for him; ; for the ‘segmental organ” appears 
really to have worked upon his ‘brain in a most serious 
way, and rendered him truly monomaniacal. All the 
lower animals, he attempted to show, possessed this “ seg- 
mental organ;” it was from this that the generative glands 
were developed, &c., andin order to support these statements 
he published most extraordinary drawings of dissections 
(which happily very few people believe in now), and treated 
the most distinguished writers, whose views differed from his, 
with contempt or abuse. M. de Quatrefages undoubtedly 
drew attention to the nature and functions of the general 
cavity of the bodies of Invertebrata before Dr. Williams, and 
throughout the researches of the former on the circulation 
and respiration of Annelida have precedence over those of the 
latter. 
_ The various organs of the Annelida are treated in, this 
chapter of 100 pages under the following heads :—1. Tegu- 
ments and general muscular system. 2. General cavity of the 
body. 3. Organs and functions of digestion —The description 
of the exsertile pharynx and its teeth and denticles in various 
genera is a specimen of the author’s great attention to details, 
and his minute acquaintance with these structures from 
personal observation. We cannot, however, agree to the 
statement that the pharynx is ever entirely everted in life by 
the Polynoina, which is, indeed, put forward somewhat doubt- 
fully ; it seems to be merely owing to a strong convulsive 
action of the muscles that this takes place, generally resulting 
from such an irritation as causes death ; and we doubt if the 
pharynx is ever withdrawn again, since the worm dies almost 
directly after its protrusion. 4. Organs and functions of 
absorption.—Under this heading the author states ‘ there 
are no special organs of absorption.” He assigns this func- 
tion to the vessels of the red fluid which are intimately con- 
nected with the intestine. 5. Organs and functions of circula- 
tion. 6.Organs and functions of respiration —'Treated separately 
as the respiration of the blood (red vascular fluid), and 
respiration of the liquid of the general cavity. ‘These two 
