de gli altri Jilosoji Peripatetici, hanno creduto esser fallacie, e ingmmi dei cristalli quelle, che altri hanno ammirate per operazioni stupende:^Happily, we have well nigh outgrown this indolent traditionalism in science. The microscope is so thoroughly identified with all recent progress in Physiology, that practical men cannot refuse to recognise its value as an instrument of research. It is now pretty generally felt and acknowledged, that assuming in different observers equal familiarity with the microscope, and equal care in its employment-what one anatomist discovers, another may readily verify. To this test the Author of the present Essay will cheerfully submit the result of his labours ; wishing his observations to be received only so far as they are confirmed by others, who may investigate the subject with the same care as he has given to it, and with the same freedom from previous bias. Mere details of micrometry, and the like, are interesting only in proportion to what flows from them. Fortunately, most of the facts in minute anatomy here recorded are important, both in their analogies, and in the consequences which they involve ; their application is, in most instances, so obvious that the reader will hardly comi^lain reference to the thymus ;-" Dicitur pomum granatum, sive culcitra, quia super ipsam sedet vena chilis et arteria in directo cordis, in loco ubi vena ascendit ad cor." HISTORICAL INTRODUCTION. 3 and was asserted in the early works of the Italian anatomists. Berengario'^da Carpi, while adopting the common belief, seems to have had some notion of the differences produced in the gland by age. Guinther^professedly followed Galen; and Vesa-lius^, in this instance, bowed to the authority which he elsewhere successfully opposed. Etienne^Valverde^Colombo®, Plater and Bauhin®, in the same century, Avith Riolan^, Vesling^°, de Marchettis", Bartholin^'^, de Muralto'^and Bidloo*^, in the next, successively repeated the doctrine, either in its original form, or with some trifling modification. A different theory, though one ascribing to the gland an equally mechanical use, was first suggested by Bidloo, in the thesis just quoted, and has been supported by Pozzi^^, 1 A. J. Bereng. Carpi Isagoge brevis, Bonon. 1523, fol. 33,-" certa adenosa caro, quaj est culcitra seu stragulum vence. .. ab auctoribus niorum et timum vocatur, et a vulgatibus nominatur animella et lacticinium ... est in cibariis usitatis saporosi gustus, maxime ilia quse reperitur in vitulis et hcedis lactantibus." Job. Guintberi Anat. institut. ex Galeni sententia. Par. 1536, lib. ii. (Annales du Museum, tom. xviii.) 1® Pozzi, Orat. dum et Commerc. Anat. Bonon. 1732. Modifications of the mechanical theory. 1® Th. Bartholin (in his Anat. quartum renovata, Leidoe, 1673) states, that he observed the fluid in 1652. ii' J. D. Horstius, jun. (Epist. med. decas. Franc. 1656, p. 85) says, that he has seen it so turgid with milk (lacte adeo intumescentem) " ut primo intuitu apostematis suspicio oboriretur." 15 Gul. Harveius, Epist. ad Riolanum ...
