ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
785 
Anatomy of Pentastomum teretiusculum.* — Prof. W. Baldwin 
Spencer has published a detailed account of the anatomy of this parasite, 
which was taken from the lung of the copper-head snake (Hoplocephalus 
superbus ), and from Pseudechys porphyriacus. In one copper-head no 
fewer than 129 specimens were to be counted in the lungs and trachea, 
of which 20 alone were males. 
In the account of the external anatomy attention is drawn to the 
primary and secondary papillae ; the cuticle consists of a very thin 
external layer, which stains more deeply than the main portion ; the 
former portion alone forms the ridges. The cuticle is secreted by 
columnar cells, between which spaces are left, through which there pass 
to the cuticle the ends of muscle-fibres and of special strands of con- 
nective tissue. 
With regard to the muscles, Prof. Spencer emphasizes the fact that, 
so far as he has been able to observe, all the muscles of the body are 
distinctly striated. In the description of the mouth and pharynx an 
account is given of five main sets of muscles. 
The mo;$t striking feature in the anatomy of Pentastomum appears 
to be the great development of glandular structures of an excretory 
nature. The author describes them under the heads of (1) hook-gland, 
(2) head-gland, and (3) parietal cells, while a body of uncertain nature 
lies above the very anterior end of the mid-gut. The author suggests 
that this rich supply of glands may be for the purpose of preventing the 
coagulation of the blood on which P. teretiusculum exclusively feeds. 
A detailed list is given of the nine sets of nerve -branches given off 
from the suboesophageal nerve-mass. On some of the papillae there are 
sense-organs well supplied with nerves, and it is suggested that their 
function is tactile : they are probably sensitive to such stimuli, for 
example, as those produced by the flow of blood through vessels close 
to them ; a stoppage in the flow, and hence in the food-supply of the 
parasite, would be detected. It is perhaps by these that the Pentastomum 
learns of the death of its host, when it wanders out from the lung in 
the characteristic way in which parasites leave the body of a dead host. 
A full account is, finally, given of the somewhat complicated repro- 
ductive apparatus of both sexes. This valuable contribution, which is 
very well illustrated, does not, from its mass of facts, lend itself to an 
abstract. 
Active Migration of Pentastomum denticulatum.j — Prof. S. von 
Batz, from the observation of a number of cases, comes to the conclusion 
that it is probable that Pentastoma are able to wander actively from the 
organs of their first host by means of the respiratory organs, whence 
they reach the air-passage, and so the outer world. As suggested by 
Gerlach, those that migrate into the air-passages and nasal cavities may 
there become sexually mature ; in this way there may be self-infection, 
and we may thus explain the rare cases of the presence of sexually 
mature Pentastoma in the nasal cavity and pharynx of herbivorous 
forms. The author supposes, however, that this active migration is a 
rare phenomenon. 
* Quart. Journ. Micr. Sci., xxxiv. (1892) pp. 1-73 (9 pis.), 
f Centralbl. f. Bakteriol. u. Parasitenk., xii. (1892) pp. 329-33. 
