The Logo for Lesson 18 is a "Calavera"

Question 18 SA-15. Here is the text reference (p. 177/2):

Azuela's story corresponds to the phase when the Revolution was becoming consolidated and bureaucratized. A series of official revolutionary political parties were organized, culminating in the &laqno;PRI - Partido Revolucionario Institucional» (translated as &laqno;Party of the Institutionalized Revolution &laqno; or &laqno;Party of the Revolutionary Institutions»). The PRI is still in power, and it maintains that the Revolution continues even after more than three quarters of a century, despite clear indications to the contrary.