THROMBOSIS OF TUE HEART. 295 



which is farthest from tho orifice of exit does not get driven 

 out ; it remains in the apex of a ventricle or an auricular appen- 

 dix as the case may be. In these regions there are a number 

 of pouched recesses, often branched and hidden, from which the 

 blood can never be expelled save by very complete contractions. 

 Such recesses do a great deal to help coagulation ; it is in them 

 that we always find the first beginnings of the process. A 

 number of little clots are often found blocking up the inter- 

 trabecular spaces of the lieart's apex, to such an extent as to fill 

 up, more or less completely, the inequalities which normally 

 exist in that reo-ion. 



§ 259. The next step is for the various thrombi to protrude 

 from the nooks in which they had their origin ; the contiguons 

 ones coalesce ; and in this way, simple clots of considerable 

 length and thickness are produced, wdiich take up a great part 

 of the heart's cavities. Their shape conforms in a general way 

 to that of tho cavity which they partially fill, and to whose 

 inner surface they arc closely applied at each systole. I have 

 seen a thrombus occupying the left auricle project through a 

 contracted mitral orifice (where it exhibited a corresponding con- 

 traction) into the left ventricle, where it again swelled ont. The 

 clots usually terminate in a rounded end, which led Laennec to 

 call them ^' vegetations globuleuses." Their colour depends on 

 the time they have existed. We seldom meet with thrombi of 

 any size which are still solid throughout. Such thrombi exhibit 

 an exquisitely laminated composition, and it is easy to see that 

 this concentric lamination begins in the most external layers of the 

 clot, and that the outermost lamellce are consequently the oldest. 



The farther changes which the thrombus undergoes depend 

 upon the fact that its peripheral layers are better able to obtain 

 nourishment than its nucleus. As a rule therefore, we find de- 

 colorisation and softening not in the oldest, but in the most 

 central parts of the entire clot, from which these changes spread, 

 layer by layer, to its surface. They may progress until we have 

 a spherical cyst filled with puriform fluid, attached to the walls 

 of the cavity by solid rootlets (the first intertrabecular coagula). 

 I need hardly add, that if the thrombus should by any chance be 

 broken up, the patient will be in innninent peril of embolism, and 

 the inflammatory and suppurati"\'e accidents which flow from 

 embolism. 



