HELKIAH CROOKE (1576-1635). Mikrokosmographia [Greek title transliterated]: A description of the body of man. London: Printed by William Jaggard, 1615.

Crooke received his medical degree from Cambridge and was prone to be a quarrelsome individual of sometimes dubious character, especially when financial matters were involved. He had several clashes with London’s College of Physicians over questions of ethical conduct.

The thirteen books of descriptive text were taken almost entirely from Bauhin’s Theatrum anatomicum.  Crooke made no secret of the fact that he took his text and illustrations from Bauhin and other material from Du Laurens. In his opening “Preface to the Chyrurgeons” he states: “My present worke is for the most part out of Bauhine for the History, Figures, and the seuerall Authors quoted in his Margents. The Controuersies are most what out of Laurentius. . . .”

The College of Physicians were disturbed because the book was to be in English and they felt the illustrations dealing with generation, conception, and reproduction were indecent, though many were taken from Vesalius. The College was unsuccessful in its attempts to have the book suppressed or altered before publication. The male and pregnant female on the title page may be an expression of Crooke’s defiance of their actions.

The book was the largest and most comprehensive English anatomy of its day, and was one of  the last English anatomies based on continental sources before the emergence of a truly English anatomical school.

At the beginning of the 17th century, it was widely believed that food was converted into blood as it passed through the digestive system. The blood was then carried to the liver where it was imbued with natural spirits and passed on to the heart for distribution through the body. Since only the blood vessels were known to the anatomists of that day, it was thought that chyle, the product of digestion, was transported to the liver by the venous system of the intestines.

This notion was corrected by Gaspare Aselli in 1627 when, by accident, he discovered the lacteal vessels in the mesentery of a dog. He incorrectly surmised that the lacteal vessels empty their contents into the liver. It was not until 1651 that Pecquet reported his discovery of the receptaculum chyli and thoracic duct. He accurately described the lacteal veins of Aselli and showed that they terminate in the receptaculum chyli and that the thoracic duct joins the venous systems at the junction of the jugular and subclavian veins.

Joannes van Horne made the same discovery quite independently and corroborated Pecquet’s findings. Later Pecquet’s work was confirmed and extended to cover the entire lymphatic system by Olof Rudbeck (1630-1702) and Thomas Bartholin. The copperplate engraving clearly depicts the main lymphatic system both in a separate figure and in the dissected abdomen and thorax of a dog.