512 Proceedings of the Association of American Anatomists 



on a separation of layers of the palmar fascia and partly on the forearm 

 flexors becoming continuous with palmar muscles. 



The flexor profundus is the first to develop by the separation of the 

 deeper layers of the forearm flexor mass together with the correspond- 

 ing layer of the palmar fascia and muscles which arise from the under- 

 surface of this deep layer of the palmar fascia persist to form the lum- 

 bricales. The flexor sublimis later separates from the palmaris longus 

 and carries off another layer of the palmar fascia together with a sheet 

 of muscle tissue attached to this ; the muscle tissue degenerates to form 

 the terminal portions of the perforated tendons. The flexor profundus 

 is a flexor perforans because it is the earliest to develop and pre-empts 

 the terminal phalanges. 



Contrary to views which have been expressed on the subject, the 

 arrangement of the flexors of the foot seems to represent a more primi- 

 tive condition than does that of the flexors of the hand. 



JSTOtE ON THE OCCUEEENCE AND SIGNIFICxlNCE OF THE MUSCULUS 

 TIBIO-ASTEAGALUS ANTICUS. By James Playfair McMuebich 

 AND E. N. Waterman. 



Two cases of the occurrence of this muscle have been described by 

 Gruber, one by Hyrtl, one by Macalister and one by Wagstaffe. The 

 last was found in connection with a defect of the fibula, as was also 

 the case now under consideration. In this the fibula was represented 

 by a slender rod of cartilage except at the malleolus, which was ossified, 

 and the muscle arose from the outer surface of the lower end of the 

 tibia and passed distally behind anterior tibial vessels and nerve to be 

 inserted into the astragalus. 



The muscle has usually been regarded as belonging to the Tibialis 

 anticus, but its relations to the tibial vessels which are interposed be- 

 'tween it and the Tibialis seem rather to suggest its association with the 

 extensor muscles. It may possibly be regarded as a portion of the ex- 

 tensor mass which has not undergone an extension into the foot. 



THE NUCLEAE CHANGES IN THE STEIATED MUSCLE CELL OF NEC- 

 TUEUS. By Albert C. Eycleshymer. 



The work was done imder the direction of Prof. Charles S. Minot 

 and while the yriter held an Austin Fellowship in the Harvard Medical 

 School. 



On the nuclear changes during certain phases of cell life we possess 

 an extensive literature, hut concerning the role of the nucleus in histo- 

 genesis we know but little. 



