SECRETORY FUNCTIONS IN HUMAN PLACENTA 507 



The cells illustrated in figures 55 to 57 are already exceedingh^ 

 large, and they are, at a glance, recognized as Marschand's 

 so-called large-type of decidual cells. On the surface there 

 is a rather thick layer, which may be divided into two of which 

 the inner one is thick and the outer thin, and they exactly 

 remind us of the definite cell membrane. The cell bodies consist 

 of plastosomes, lipoid granules, and structureless stroma. The 

 plastosomes are mostly long rods or threads, some being more or 

 less peculiarly curved and the quantity of plastosomes is variable. 

 The lipoids differ also in point of size, density, quantity, 

 etc. What is worth our noting is that there is no vacuolar 

 formation to be found in these cells. The nuclei are large, clear, 

 and foamy. The nuclear network is especially conspicuous in 

 figures 56 and 57. Figures 58 to 61 show the definite form 

 commonly belonging to the so-called decidual cells of large type. 

 In these cells the cell membrane is remarkably thick, and the 

 distinction between the inner and outer layers is always clear. 

 What deserves our special attention at this juncture is that the 

 outer layer contains, in most cases, a kind of granular body 

 which is somewhat large and yet irregular in size and stained 

 a dark color. The cell bodies consist of a large quantity of 

 plastosomes and homogeneous stroma. The plastosomes are 

 mostly long rods, and they sometimes appear extremely elongated 

 in the shape of threads (fig. 61). They are distributed equally 

 all over the cell bodies, although they sometimes tend to appear 

 more or less in groups. The plastosomes in these large cells 

 have, in general, very slow staining properties, and, therefore, 

 they are a very difficult subject to be dealt with from the tech- 

 nical point of view. The nuclei are foamy and dark-colored, 

 and the nuclear networks are indistinct. 



The cells illustrated in figures 62 to 69 differ from those de- 

 scribed above, and they all lack the plastosomes. Even in the 

 most excellent stained preparations these cells appear within 

 the decidual tissues in small numbers, for the most part more 

 or less in groups, scattered like islets, so that it is, as a matter 

 of course, incomprehensible that here alone the plastosomes 

 are hard to be demonstrated. However, as, in consideration of 



