398 THE PHYSIOLOGY OF REPRODUCTION 



with iron-hsematoxylin, knobs may be seen at the bases basal 

 corpuscles or blepharoblasts and they may constitute the motor 

 centre for the ciliary beats. But no movements have yet been 

 observed, and von Lenhossek 1 calls them " stereozilien," or stationary 

 cilia, suggesting that they may help to break down vessel-walls 

 during the burrowing of the syncytium into the serotina. Sometimes 

 they appear not to project free on the surface but to lie in the 

 superficial stratum ; then lighter and darker striae alternate, and it 

 is this appearance which has led to the name " striated edge." 

 Bonnet 2 ingeniously remarks that it proves the fretal origin of 

 the syncytium, because, if it were uterine, the free edge would be 

 formed by the bases of maternal cells, and they could not possess a 

 " Biirstenbesatz." The same appearance has been noted in intestinal 

 epithelium, but its significance is unknown. In the placenta Graf v. 

 Spee 3 attributes the appearance to the teasing out of the surface of 

 the protoplasm, and looks on it as evidence of a strong flow of fluid 

 through the syncytium. It has also been suggested that the thin 

 rods may be hollow and act as pores by which nutriment may enter 

 the syncytium, or by which a secretion of the syncytium may pour 

 out in order to prepare the constituents 'of the maternal blood for 

 their transference to the foetus. 



It is still undecided whether the syncytium possesses amoeboid 

 motility. V. Lenhossek examined a human ovum several minutes 

 after its removal from the uterus and observed, as has already been 

 stated, no ciliary movements ; but he considered it not improbable 

 that the syncytium underwent changes of form. Hofbauer tried 

 unsuccessfully to demonstrate such movements in a specimen 

 examined immediately after its removal. 



The core in young villi consists of a matrix, homogeneous or 

 delicately fibrillated. In it are placed the blood-vessels and con- 

 nective tissue corpuscles with long branching processes, which form 

 a network in the matrix, and probably provide a series of lymph- 

 channels. Kastschenko also described special cells, with large nuclei, 

 which he took to be wandering cells. But Lenhosse'k proved that 

 they existed before leucocytes or lymph-cells appeared, and must, 

 therefore, be formed in the villi and derived from mesoblastic cells. 

 Hofbauer has observed them also in the lumen of the fretal vessels, 

 and suggests a possible transformation to leucocytes. 



Our ideas upon the function of syncytia are largely based on 



1 V. Lenhoss6k, Verhandl. d. anat. Kongresses in Halle, 1902. See Centralbl. 

 f. Gyncik., 1904, Nr. 7. 



2 Bonnet, " Uber Syncytieri, etc.," Monatsschr. f. Geburtsh. u. Gyncik., vol. 

 xviii., 1903. 



3 Graf v. Spee, " Neue Beobachtungen iiber sehr friihe Entwickelungsstufen 

 des raenschlichen Eies," Arch.f. Anat. u. Phys., Anat. Abth., 1896. 



