Paper, 'Researches into the structure and development of a newly discovered parasitic animalcule of the human skin: the Entozoon folliculorum' by Erasmus Wilson

Description

While engaged in researches on the minute anatomy of the skin and its subsidiary organs, and particularly on the microscopical composition of the sebaceous substance, Wilson learned that Dr. Gustow Simon of Berlin had discovered an animalcule [microscopic organism] which inhabits the hair follicles of the human skin. Wilson believes that he has found the parasitic animals in question, having proceeded to investigate more fully and minutely than Dr. Simon had done the details of their structure, and the circumstances of their origin and developement. They exist in the sebaceous follicles of almost every individual, but are found more especially in those persons who possess a 'torpid skin'; they increase in number during sickness, so as in general to be met with in great abundance after death. In living and healthy persons, from one to three or four of these entozoa are contained in each follicle. They are more numerous in the follicles situated in the depression by the side of the nose; but they are also found in those of the breast and abdomen, and on the back and loins. Their form changes in the progress of their growth. The perfect animal presents an elongated body, divisible into a head, thorax, and abdomen. From the front of the head proceed two moveable arms, apparently formed for prehension: and to the under side of the thorax are attached four pairs of legs, terminated by claws. The author distinguishes two principal varieties of the adult animal; the one remarkable for the great length of the abdomen and roundness of the caudal extremity; whilst the other is characterized by greater compactness of form, a shorter abdomen, and more pointed tail. The first variety was found to measure, in length, from the one-100th to the 45th, and the second, from the one-160th to the 109th part of an inch. The author gives a minute description of the ova of these entozoa, which he follows in the successive stages of their developement.

There are indications throughout the paper as to where figures and illustrations should be inserted. Annotations in red ink throughout.

Subject: Dermatology / Parasitology

Received 29 December 1842. Communicated by Dr [Robert Bentley] Todd.

The paper was published in volume 134 of Philosophical Transactions as 'Researches into the structure and development of a newly discovered parasitic animalcule of the human skin—the entozoon folliculorum'.

An abstract of the paper was published in volume 4 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'Researches into the structure and developement of a newly discovered parasitic animalcule of the human skin, the Entozoon folliculorum'.

Reference number

AP/26/20

Earliest possible date

1843

Physical description

Ink on paper

Page extent

62 pages

Format

Manuscript