LACTIFEKOUS TISSUE. 31 



cond, the spiral vessel is terminated by a conical extremity, 

 and of course may be considered an elongated cell. Third, 

 there is noditlerence in their constitution, tlicir only ditlerence 

 beini'-in their length, and in tlicir earliest stage arc said to be 

 undistinguishable Ironi a cell. The diticrence of length 

 cannot in the present state of our knowledge constitute a suf- 

 ficient distinction, for Mirbcl, as well as others, have seen a 

 cell develop itself into a tube terininatcd by a point. Mr. 

 Quickett has shown that the spiral vessels are developed in 

 the same manner as the cellular tissue, as described in 23 — 

 that it is at first very diflicult to distinguish the spiral vessel 

 from the cell ; but that soon the vessicle, destined to become 

 a spiral tube, elongates, and the eytoblast disapj)cars. The 

 contained fluid becomes filled with minute granules, which 

 increase sliiihtlv in size, and beji-in to arrange themselves on 

 the internal surface of the tube, in a regular and determinate 

 manner, accordiug to the spire formed. After the arrange, 

 ment of these molecules, matter is deposited to fill up the spa- 

 ces between them, and thus the spire becomes formed. The 

 al)ove are the most important points applicable to the subject, 

 taken I'rom a paper recently published by Mr. Quickett, and 

 certainly ihey give a most beautitiil exhibition of nature's work- 

 manship, llaspail, although, in many respects, singular in 

 his hypothesis, asserts that cells have the power of producing 

 vessicles both from their internal and external surfaces, and 

 that those produced by the internal surface are globular, and 

 form the true cellular tissue, while those generated on the ex- 

 ternal surface are produced in length only, and form every 

 other kind of tissue. 



We are attached to no theory on the subject, and we have 

 simply stated our conclusions drawn from the various facts 

 observed by ourselves and those recorded by others, and the 

 above opinions 've would readily yield, should future discove- 

 ries prove them untrue. The only object at which we aim 

 is the inculcation of truth. Nature is our theme, and he that 

 would enter on an investigation of her works with any other 

 spirit than tliat of humility, accompanied with a desire to take 

 her as she presents herself in all her varied forms of harmony 

 and beauty, profanes her sacred temple and forfeits, by a sac- 

 rilegious spirit, all claims as her votary. Our limits forbid our 

 introducing here, numerous experiments or advancing many 

 arguments ; these must be left for more extended treatises, 

 and the lecture room. The writings above quoted may be 

 conealted, where all that is at present known on this intricate 

 and interesting subject may be found. 



