INDEX OF PART I. 



ABDOMINAL stalk, 46 

 Accessory thyroids, 1 1 1 

 Alae nasi, 96 



Albrecht on auditory ossicles, 168 

 Alecithal ova (a, not, \iJKvdos, oil-bottle), defi- 

 nition, 9 



invagination of, 22 



Alimentary canal, development of, 99 

 Allantoic arteries. See UMBILICAL. 



fluid, 46 



tube, 36 



Allantois (a\\as, sausage, ei5os, form), formation 

 of, 43 



first appearance of, 44 



structure of, 44 



in what animals found, 45 



hypoblastic sac of, 46 



pedicle of, 46 



variation of period of development, 46 



connection, with alimentary canal, 101, n. 



with bladder, 122 



Amnion (d,tmoj/, a bowl in which victim's blood 

 was caught, the caul), earliest appear- 

 ance of in human embryo, 46 



false, 42 



formation of, 42 



in guinea pig, 43, 46 



resulting from invagination, 24 



true, 42 

 Amniota, 42 

 Amphibia, liver in, 112 



Wolffian duct in, 118 



heart in, 136 



Amphioxus (a^tyi, double, o|vs, a point), ale- 

 cithal ova of, 9 



invagination of blastoderm of, 22, 24 



origin of mesoblast in, 22, 26 



mesenchyme in, 27 



notochord in, 34 



mesoblastic somites in, 37 

 Amygdalae (a^trySoA.^, almond), 66 

 Anal membrane, the, 108 



Analogy, avd, according to, \6yos, ratio), defi- 

 nition of, 4 



examples of, 4 

 Anatomy, definition of, I 



departments of, I 

 Angelucci on zonule of Zinn, 87 

 Annelida (annellus, little ring), 2 

 Anterior perforated space, 79 

 Anus, formation of, 108, 128 

 Aorta (aopT-f), aeipu, to lift), primitive, formation 

 of, 38 



descending primitive, 146 



arch of, 148, 150 



bulb of, 144, 147, .148 



descending permanent, 150 

 Aortic arches. See ARTERIAL ARCHES 



VOL. I. 



Aqueduct of Sylvius, 62, 67 



Archenteric cavity, primitive (apx^l, beginning, 



fvrepov, intestine), 26 

 Archiblastic cells of His, 25 

 Arteria centralis retinae, 85, 87 

 Arterial (aortic) arches, formation of, 38, 146 



division of aortic septum by, 144 



origin of principal arteries from, 146, 147, 

 148 



destination of fourth and fifth, 150 

 Arteries (aprrjpla, aipw, to lift), development of, 

 146 



from arterial arches, 148, 149 



from arches in birds, 150 



ascending pharyngeal, 148 



auricular, 148 



basilar, 149 



carotid, 148, 150 



common iliacs, 147 



innominate, 150 



intercostal, 149 

 nter-segmental, 149 



lingual, 148 



maxillary, 148 



middle sacral, 147 



occipital, 148 



pulmonary, 148, 150 



subclavian, 150 



temporal, 148 



umbilical, 44, 146, 156 



vertebral, 149 



vitelline, 40 



Arthropoda (&pQpov, a joint, TTOUS, a foot), seg- 

 niental plan of, 2 



centrolecithal ova of, 8 

 Aryepiglottic folds, 103 



Arytenoid cartilages (apvTau/a, a pitcher), 103 

 Ascaris megalocephala, polar globules observed 

 in, 9 



fertilisation in, 11, 12 



segmentation of, 16 

 Auditory pit, 89 



vesicle, 89 



nerve, 78, 89, 93 



ossicles, 167, 1 68 

 Auricular canal, 142 

 Axis, primitive skeletal, 2 



BAER, VON, zona pellucida of, 6 



on bilamination of middle layer of blas- 

 toderm, 23 

 Balfour, F. M., on amnion and allantois, 45, n. 



blastodermic layers, nomenclature of, 23 



ccelom, typical development of, 24 



head cavities, 161 



limbs, 163 n. 



lens-capsule, 87 



