Photon emission (PE) and light-induced photon emission(LPE) of intact brains isolated from chick embryos have been measured by using the single photon counting device. Experimental results showed that the intensity level of photon emission was detected to be higher from intact brain than from the medium in which the brain was immerged during measuring, and the emission intensity was related to the developmental stages, the healthy situation of the measured embryos, and the freshness of isolated brains as well. After white light illumination, a short-life delayed emission from intact brains was observed, and its relaxation behavior followed a hyperbolic rather than an exponential law. According to the hypothesis of biophoton emission originating from a delocalized coherent electromagnetic field and Frohlich’ s idea of coherent long-range interactions in biological systems, discussions were made on the significance of photon emission in studying cell communication, biological regulation, living system’s relevance to its environment, and also on the relations between the detected photon emission and the coherent electromagnetic field. The detected photon emission should be comprehended in the manner of the interactions between the intrinsic fields within the living systems and their environmental external fields
