Brian Greene: "How Einstein Changed the World. In March of that year he argued that light, long described as a wave, is actually composed of particles." https://www.scientificamerican.com/article/how-einstein-changed-the-world/
"If light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd...the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations." Banesh Hoffmann, Relativity and Its Roots, p.92 https://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768
"Einstein's March paper treated light as particles, but special relativity sees light as a continuous field of waves." http://www.pbs.org/wgbh/nova/einstein/genius/
"The two first articles (January and March) establish clearly a discontinuous structure of matter and light. The standard look of Einstein's SR is, on the contrary, essentially based on the continuous conception of the field." http://arxiv.org/ftp/physics/papers/0101/0101109.pdf
Albert Einstein (1954): "I consider it entirely possible that physics cannot be based upon the field concept, that is on continuous structures. Then nothing will remain of my whole castle in the air, including the theory of gravitation, but also nothing of the rest of contemporary physics." John Stachel, Einstein from 'B' to 'Z', p. 151 https://www.amazon.com/Einstein-B-Z-John-Stachel/dp/0817641432
"If light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd...the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations." Banesh Hoffmann, Relativity and Its Roots, p.92 https://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768
"Einstein's March paper treated light as particles, but special relativity sees light as a continuous field of waves." http://www.pbs.org/wgbh/nova/einstein/genius/
"The two first articles (January and March) establish clearly a discontinuous structure of matter and light. The standard look of Einstein's SR is, on the contrary, essentially based on the continuous conception of the field." http://arxiv.org/ftp/physics/papers/0101/0101109.pdf
Albert Einstein (1954): "I consider it entirely possible that physics cannot be based upon the field concept, that is on continuous structures. Then nothing will remain of my whole castle in the air, including the theory of gravitation, but also nothing of the rest of contemporary physics." John Stachel, Einstein from 'B' to 'Z', p. 151 https://www.amazon.com/Einstein-B-Z-John-Stachel/dp/0817641432