LUCERN A RLE AND THEIR ALLIES. 97 



view we have hesitated slightly as to whether this stratum is altogether separate 

 from tlie opsomyoplax and the oomyoplax. The forms of the histological elements 

 are different enough, as we shall show presently, and have homological relations 

 distinct from each other; but we believe that the cJiondromi/oplax must be looked 

 upon in the light of an elastic connective tissue of the muscular layer, and interme- 

 diate between it and the adjoining layers, the opsoijhracjma on one side and the 

 gastrophragma on the other. The fibrilla? of the tissue (Ji'js. 53, 74, 77, i, //) are 

 highly elastic ; but in no other respect do they exhibit any affinity with the muscu- 

 lar fibrilla?. They are purely homogeneous throughout, with not a trace of any- 

 thing like a nucleus ; in fact, they have more of the appearance of aciniform streaks 

 in a homogeneous, jelly-like mass than aught else we can compare them with. 

 They seem to be direct prolongations of the fibrillse of the muscular layer (??i), but 

 that they are not such is proved by their well-marked histological differences. 

 There can be no doubt that the muscular fibrillae confine themselves strictly within 

 the horizon of the opsone Tjoplax, as we have illustrated most fully in the tentacles, 

 and that the fibrillfe of the cliondromtjopJax alone stretch at right angles to the 

 surface of the layer, directly across its thickness. Consequently, in a section of 

 the depth of this layer, it appears to be transversely striated. The fibres do not, 

 however, always trend through the layer very strictly at right angles, but more or 

 less obliquely to the surface ; nor are they of equal breadth throughout, but taper 

 gradually from a base of considerable width to an infinitesimal point, often extend- 

 ing two-thirds or three-fourtlis through the layer. As they are based on the oppo- 

 site faces of this layer, their tapering points meet and cross each other at the; 

 middle of the thickness of the stratum intervening, as it were, just as the bristles 

 of two brushes do when forced together face to face.' 



' (A) The question here very naturally arises as to wliat is the niodo of origin of these fibrillae. 

 In most conneetive tissue, as is well known, we may find nuclear bodies scattered here and there 

 among the fibrillag, bnt in that which we have now in hand there is nothing of the kind. Have we 

 not here then an independent fibrillization of a cytoblastema ? If "N'irchow and Beale and their 

 numerous adherents admit that a cell need not have a cell-membrane, and requires only the ivresence 

 of some one concentrated material as the centre of ceutripeto-centrifugal changes and developments 

 in order to be a cell, or " elevientary part," what must we call these sell-originating fibpllae of the 

 chondromyopla.x ? The same question applies with equal, if not greater, force to the muscular fibrillae 

 of Ctenophora;, and our inferences arc the same. We cannot see that they lie within the boundaries 

 of a "cell-territory" of Yirchow ; nor at any time or age have we detected "germinal matter" of 

 Beale among them. Why should they not be classed as the original " elementary parts'" ? They 

 seem to have originated spontaneously, and we feel compelled, therefore, to admit that they have all 

 the value of cells in the most modern acceptance of the term. We are the more easily led to uilopt 

 this view after having convinced ourselves that cells so-called (no matter whether constitnled accord- 

 ing to the older histologists, or according to the most recent theory) are, after ail, of secondary 

 importance, and that the cytohlaslema (which we do not distinguish from intercellular substance) 

 is the main and essential element, the potential |)rogenitor of all tissues, and that it projects itself 

 into the utmost future of thc-living body by a process of self-proliferation. Through this, and this 

 only, can a true law of continuous development be illustrated ; whilst the various forms of cell-tissue, 

 and fibre-tissue, and bone-tissue, etc. etc., are but the disjointed, collateral developments, each one 

 irrespective of the other, from the continuous, onward stream of cytoblastema. Among the Protozoa, 

 particularly the Amoeboids and their Rhizopodic congeners, the cytoblastemic condition of the ovum 

 is continued unchanged, as to form, in the adult stage ; and so, as wo have said in a previous para- 

 13 March, 1878. 



