APPENDIX III 373 



Malpighian (from Malpighi, an Italian anatomist, 1628-1694) ; Mal- 



pighian (renal) corpuscle. 

 MAMMA (L. breast), the breast of a mammal; a combining form, mam- 

 mary glands, mammary artery. 

 Mammalia (L. viavima), a class of vertebrates with mammary glands 



and hair. 

 MAN.\TEE (Spanish manati, a sea cow), a genus of aquatic mammals, 



Order Sirenia. 

 MANDIBLE (L. mandibula, jaw), the lower jaw of a vertebrate. 

 Manis (L. manes, good), a genus of Old World edentates; the scaly 



ant-eater; a mammal covered with large horny scales. 

 Marsupialia (L. marsupium), a sub-class and order of mammals which 



lack a placenta, and have an abdominal pouch in which the immature 



young remain for some time after birth. 

 MARSUPIUM (L. a pouch), a combining form, marsipobranch, marsupial. 

 MASSETER (G. mascter, a chew), one of the larger muscles of the jaw. 

 MASTOID (G. mast OS, breast, plus eidos, form), a rounded protuberance, 



as the mastoid process of the skull. 

 MAXIMUS (L. greatest). 

 MEATUS (L. meatus, a passage, from meo, to go), any conspicuous 



passage, as the external meatus of the ear. 

 Meckel's cartilage (from Meckel, a German anatomist, 1781-1833), the 



cartilage of the lower jaw of the vertebrates; above the elasmobranchs 



the cartilage is surrounded by dermal bones; its posterior end ossifies 



as the articular bone. See malleus. 

 medius (L. middle) ; as, median, toward the middle. 

 meninges (G. meninx, a membrane) ; plural of meninx. 

 meninx (G. a membrane), a connective tissue covering of the central 



nervous system; pia mater, arachnoid, and dura mater in the 



mammals. 

 mero (G. meros, part), a combining form; epimere, h3Tomere. 

 MEROBLASTic (G. meros, plus hlastos, germ), a type of cleavage in which 



only the protoplasm divides, leaving the yolk mass uncleaved; typical 



of large yolked eggs. 

 MES, MESO (G. mesos, middle), a prefix; mesorchium, mesoderm. 

 MESENTERY (G. mesos, plus cnteron, intestine), the band of tissue which 



suspends the viscera, developing from the hypomere, and continuous 



with the peritoneum. 

 MESODERM (G. mesos, plus derma, skin), the middle layer of the three 



primary germ layers, lying between the ectoderm and endoderm. 

 MESOMERE (G. mesos, plus meros, a part), the small portion of the meso- 

 dermal somite connecting the epimere with the hyomere; equivalent 



of nephrotome. 

 MESONEPHROS (G. mesos, plus nephros, kidney), the middle kidney of 



the vertebrate; it develops posterior to the pronephros, and at a 



later date; and anterior to the metanephros; the functional kidney of 



the anamniotes. 

 MET, META (G. over, after, on the farther side of), a combining word. See 



following definitions. 

 METANEPHROS (G. meta, plus nephros, kidney), the functional kidney ot 



amniotes, partly serially homologous with the more anterior kidneys. 



See mesonephros. 



