SKCRKTOKY I'll KNO.M ICNA IN SILK (.LAND. 417 



lumen in a very definite- way. There is no evidence that mito- 

 chondria actively produce secretion but only the indication that 

 they may participate in the process. That mitochondria are 

 present in the reservoir and conducting regions but that here 

 they do not show polarity seems to indicate that mitochondria 

 may be present to perform other functions than that of partici- 

 pating in secretory activity. Activity is occurring in both the 

 middle and anterior regions, although not secretory activity. 

 The middle portion appears to be a storage place for secretion 

 where possible modifications of the secreted material may take 

 place, for example, a condensation and compression. The 

 secreted material then passes through the anterior conducting 

 portion . Tanaka (' 1 1 ) is the only investigator who has suggested 

 any possibility of the existence of secretory function in the 

 anterior region, and this probably only in the embryonic stages. 

 The usual interpretation is that this region serves as a duct for 

 the passage of secretion. In this case, the presence of mito- 

 chondria would seem to indicate that some activity exists within 

 the cell, possibly of general metabolic nature. 



(d) Golgi Bodies. In preparations of glands fixed by the 

 Mann-Kopsch, and by the Champy method, no structures have 

 been found which could be interpreted as true Golgi bodies. 

 In silk gland cells of H. cunea impregnated with osmic acid, 

 numerous fine dark granules appear (Fig. n), that are dis- 

 tributed very abundantly along the periphery of the cell-body 

 and scattered more generally toward the lumen. These fine 

 granules are present in all regions of the gland and always 

 characteristically more abundant toward the periphery of the 

 cell. In the extreme posterior tip of the gland, the granules 

 appear grouped as a dense border which gradually becomes more 

 disperse toward the lumen. In cells of the secreting region, 

 groups of large, black bodies, spherical in shape and usually 

 situated toward or near the lumen or the periphery are common 

 and may be followed through several sections of a series. 



Miss Murray ('26) describes a condition in the follicle cells 

 of the cricket which seems quite similar and her figures compare 

 closely with the condition found in the spinning-gland cell. 

 With regard to her observations, she states (p. 223) that "In 



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